After failing to score in their opening two games – a 1-0 loss to LA Galaxy and a goalless draw with Vancouver Whitecaps – City hit the lead after only seven minutes, with Alexander Callens rifling home after Montreal failed to clear their lines from a corner.
Santiago Rodriguez spectacularly chipped Sebastian Breza to double the margin on 20, but only after Montreal gifted City possession in an attempt to play out from their own half.
Zachary Brault-Guillard pulled one back for CFM, but following further City goals from Telles Magno and Thiago Andrade, the scoreline arguably belied the performance.
Douglas Costa opened his account in the MLS later on Saturday, scoring the equaliser in LA Galaxy's 3-2 loss away to Seattle Sounders.
Javier Hernandez gave the Galaxy a shock lead in the sixth minute, after fine link-up play between Raheem Edwards and Kevin Cabral, but the Sounders fought back to lead before the interval – with goals from Jordan Morris and Fredy Montero.
Costa drew the visitors level from the dead ball after 48 minutes, wrong-footing Stefan Frei, but Xavier Arreaga headed home in the 72nd to give the Sounders their first win of the season.
Los Angeles FC continued their unbeaten start to the season, meanwhile, grinding out a 2-0 win against a 10-man Inter Miami at DRV PNK Stadium.
A deflected Carlos Vela pass put Kwadwo Opoku through on the stroke of the interval, and the 20-year-old Ghanaian finished with composure. That didn't spell the end of events in the first half, though, as Brek Shea was given a straight red card in injury time.
LAFC had six shots for the match compared Inter's seven, despite 53 per cent possession and an extra man. However, an Ismael Tajouri free-kick crept inside Inters back post in the 82nd minute to secure the win.
Steve Cherundolo's side are equal top in the Western Conference with Real Salt Lake, who defeated New England Revolution 3-2. Austin FC couldn't keep pace in the final Saturday game, however, going down 1-0 away to Portland Timbers through a Bill Tuiloma goal.
Columbus Crew share the lead in the Eastern Conference, following their 2-1 win over Toronto FC. They are joined by Philadelphia Union, who defeated San Jose Earthquakes 2-0.
A Darwin Quintero brace handed Houston Dynamo a 2-0 win against Vancouver Whitecaps, while Brandon Vazquez scored a double of his own in FC Cincinnati's 2-1 win at Orlando City.
FC Dallas, Chicago Fire and Colorado Rapids respectively secured 2-0 victories over Nashville, DC United and Sporting Kansas City in Saturday's other games.
Tesho Akindele's header after 12 minutes to give Orlando City a 1-0 victory against Toronto FC, giving the Florida side three wins and three draws through six matches.
The Revolution saw off 10-man New York Red Bulls 3-1 behind first-half goals from Gustavo Bou and Tajon Buchanan and an Adam Buksa tally late to seal it.
Two late strikes from Lucas Zelarayan helped the Columbus Crew stun New York City FC 2-1 after the home side led into the 82nd minute.
Felipe Mora's second-half brace and a penalty from Diego Valeri lifted Portland to a 3-0 triumph over 10-man LA Galaxy.
Diego Rossi scored twice before the break as Los Angeles FC held on to defeat Colorado Rapids 2-1.
Houston's Memo Rodriguez and Maximiliano Urruti provided the winning margin for Houston as they won 2-1 over Vancouver.
Sporting Kansas City continued their strong start, shaking off an early San Jose Earthquakes goal from Javier Lopez en route to a 3-1 win as Jaylin Lindsey, Alan Pulido and Daniel Salloi found the back of the net.
Luka Stojanovic lifted Chicago Fire past Inter Miami 1-0 for their first win of the season, and FC Cincinnati also emerged victorious for the first time this term with a 2-1 win at Montreal.
Real Salt Lake escaped with a 2-2 draw at FC Dallas thanks to Damir Kreilach's goal after 86 minutes.
The Galaxy, who were without Javier Hernandez due to injury and Jonathan dos Santos, Efrain Alvarez and Sebastian Lletget to Gold Cup call-ups, were brushed aside by Dallas who were last in the Western Conference prior to the game.
Pepi, who turned 18 in January, becomes the youngest player in MLS history to net a hat-trick.
The teenager netted twice in the first half before completed his treble with a low shot from the edge of the box in the 50th minute.
Substitute Jader Obrian added another in the 88th minute as Dallas moved up to 10th in the west, while the Galaxy are third but are winless in their past three.
Carlos Vela got on the scoresheet as LAFC came from two goals down to rescue a 2-2 home draw with struggling Vancouver Whitecaps.
Colombian pair Deiber Caicedo and Cristian Dajome had put the Whitecaps two-up inside the first 38 minutes, before Vela pulled one back in the 40th minute.
Diego Palacios provided the pass for fellow Ecuadorian Jose Cifuentes to level in the 75th minute.
Charles Sapong scored twice as Nashville SC moved up into second spot in the Eastern Conference with a 3-0 victory over Cincinnati.
Toronto maintained their good recent run with a 2-1 win at Chicago Fire, while Minnesota United scored twice in the final 20 minutes to win 2-1 over Portland Timbers.
San Jose Earthquakes drew 1-1 with Houston Dynamo and Real Salt Lake won 3-0 over Colorado Rapids.
A 2-1 victory over the Chicago Fire saw Philadelphia push three points clear of Toronto in the Eastern Conference, and for the Supporters' Shield, which they are bidding to win for the first time.
Kacper Przybylko opened the scoring from the penalty spot approaching the half-hour mark, following a handball in the area.
Chicago's chances of a comeback were dealt a blow nine minutes before half-time, Francisco Calvo sent off after a tackle on Alejandro Bedoya.
However, they managed to find an equaliser prior to the break as Robert Beric headed in from close range.
But Philadelphia scored what proved to be the winner in the 65th minute, when Cory Burke headed in a cross from Olivier Mbaizo.
According to Opta, Union became the first team to win their first eight home matches of an MLS season since San Jose in 2002, when the Earthquakes claimed their first 10.
The Timbers clinched a spot in the play-offs thanks to a 5-2 thrashing of the struggling LA Galaxy.
Jaroslaw Niezgoda scored a brace for Portland, who were 3-0 up after 30 minutes following Diego Valeri's penalty.
Eryk Williamson and Andy Polo also netted as the Timbers thrashed the Galaxy, who are bottom of the Western Conference.
Portland became the first team with multiple five-goal games against an opponent in a single MLS season since the Fire against the New York Red Bulls in 2008, having thrashed the Galaxy 6-3 earlier this month.
Chris Wondolowski scored a brace as the Earthquakes enjoyed a 2-0 win over Real Salt Lake.
It was his 24th multi-goal game in MLS. Only Landon Donovan (32) has more.
The New York Red Bulls left it late to edge the New England Revolution 1-0 and reach the play-offs, Sporting Kansas City overcame Cincinnati 1-0 and Orlando City thrashed Atlanta United 4-1.
New York City upset Toronto 1-0, Minnesota United beat the Colorado Rapids 2-1, DC United were too good for Columbus Crew 1-0, Dallas claimed a 2-1 win over Inter Miami and Los Angeles FC were 2-1 victors over the Houston Dynamo to clinch their play-off place.
Union, who are fifth in the Eastern Conference, went behind in the 10th minute when Przemyslaw Frankowski headed in Boris Sekulic's cross.
Chicago were reduced to 10 men when Wyatt Osmberg received a straight red card in the 34th minute, after VAR review, and Philadelphia capitalised from the ensuing free-kick.
German defender Kai Wagner scored the equalizer with a shot which went under the jumping Chicago wall.
Daniel Gazdag spurned a chance for Philadelphia with a header which went wide in the 52nd minute, while Union substitute Ilsinho fluffed a late volley.
Philadelphia have now won only one of their past seven games.
Nashville edged their way up to third in the Eastern Conference with a 1-1 draw at lowly Toronto.
Omar Gonzalez had headed Toronto ahead from a 19th-minute quick free-kick, but Robert Castellanos levelled before half-time from a long throw-in.
Union scored first-half goals from Alejandro Bedoya and Daniel Gazdag, while Sergio Santos had a goal disallowed on the stroke of half-time, as Philadelphia got some revenge after last season's Eastern Conference final defeat to City.
Bedoya put Philadelphia ahead in the 12th minute, but City thought they had an avenue back into the game when referee Ted Unkel awarded them a penalty and sent off Jack Elliott for a 28th-minute last-man push on Santiago Rodriguez.
However, VAR intervened and determined that Rodriguez had illegally used his hand in the lead-up, meaning the penalty and red card were overturned.
The win was Philadephia's first at Yankee Stadium and came despite City bossing the possession count with 74 percent.
Former Liverpool and Bayern Munich attacker Xherdan Shaqiri netted his first MLS goal as Chicago Fire won 3-1 over Sporting KC.
Shaqiri scored from the spot in the 50th minute to make it 2-0 as Chicago extended its unbeaten start to the new season with Kacper Przybylko hitting a double.
Jesus Ferreira scored a first-half hat-trick as Dallas defeated Portland Timbers 4-1 in a sign of intent for the forward ahead of USA's upcoming World Cup qualifiers.
All three of Ferreira's goals came in a 10-minute span, marking his first-ever MLS hat-trick.
Gonzalo Higuain scored, but Inter Miami remain winless this term after a 3-1 loss away to last season's strugglers Cincinnati.
The result leaves Phil Neville's side with an MLS-worst record of one point from four games, having conceded 10 goals and only scored two.
Karol Swiderski netted a double as Charlotte upset New England Revolution 3-1, while Luis Amarilla's 32nd-minute strike lifted Western Conference leaders Minnesota United past San Jose Earthquakes 1-0.
Tyler Pasher's 90th minute goal salvaged a 1-1 home draw for Houston Dynamo against Colorado Rapids, while 10-man Atlanta United scored twice in the final five minutes to rescue a 3-3 draw with Montreal.
Facundo Torres' early goal got Orlando City past LA Galaxy 1-0, Bob Bradley's Toronto knocked off DC United 2-1 and Real Salt Lake edge 10-man Nashville 2-1.
Javier 'Chicharito' Hernandez scored twice for the Galaxy in a 3-3 draw with Minnesota United on Decision Day, but RSL's last-gasp 1-0 win over Sporting Kansas City changed the landscape of the Western Conference.
RSL pipped the Galaxy – without post-season football for the second straight campaign – to the seventh and final play-off spot on victories for the season via a 95th-minute winner, having finished level on 48 points at the end of 34 rounds.
Minnesota finished fifth to clinch a post-season berth in the west, along with sixth-placed Vancouver Whitecaps, who drew 1-1 against Seattle Sounders.
Seattle's stalemate and Sporting KC's late loss allowed Colorado Rapids to secure top seed in the Western Conference following a 5-2 rout of Los Angeles FC, who were eliminated as a result.
In the Eastern Conference, Orlando City beat Montreal 2-0 for a spot in the play-offs, along with Atlanta United (2-1 over FC Cincinnati) and New York Red Bulls – the latter using a 1-1 draw against Nashville to extend their post-season streak to 12 years.
Supporters' Shield winners New England Revolution lost 1-0 to already eliminated Inter Miami, Portland Timbers eased past lowly Austin 3-0, DC United defeated Toronto 3-1, 10-man New York City drew 1-1 with Philadelphia Union and reigning champions Columbus Crew – who will not defend their title – beat Chicago Fire 2-0.
Chris Wondolowski scored in the San Jose Earthquakes' 1-1 draw against Dallas before the league's all-time leading scorer announced his retirement.
Clark – aged 17 years, four months and 18 days – became the youngest player to score in his first two MLS appearances on Wednesday, per Opta.
Hours after joining the Red Bulls, Clark capped his debut with a goal in Saturday's 1-0 win over Atlanta United.
Clark became the youngest player to score his maiden goal for the Red Bulls since Jozy Altidore in 2006.
He continued where he left off against Toronto, netting the equaliser with 13 minutes remaining midweek.
Following Alejandro Pozuelo's 23rd-minute penalty, Clark earned the visiting Red Bulls a point by firing a shot into the top corner of the net from outside the box.
The Red Bulls are seventh in the Eastern Conference, while Toronto – already play-off bound – remain top through 18 games.
Elsewhere, reigning Supporters' Shield holders Los Angeles FC and struggling LA Galaxy were beaten.
Lucas Cavallini's brace lifted Vancouver Whitecaps to a 2-1 victory against fourth-placed LAFC.
Canada international Cavallini has now scored in back-to-back games after finding the net just twice in his first 11 MLS matches for the Whitecaps, who climbed up to eighth in the standings and in the play-off positions.
As for the Western Conference's bottom side – the Galaxy – they were swept aside 4-0 by San Jose Earthquakes in the Cali Clasico.
Former Manchester United and Real Madrid striker Javier Hernandez was substituted early in the second half, with the Galaxy only managing four goals in the 652 minutes 'Chicharito' has been on the pitch this season.
It was a sixth consecutive defeat for the slumping Galaxy as the Earthquakes moved within a point of LAFC in the west.
Wednesday's scheduled Minnesota United-Chicago Fire fixture was postponed due to a suspected coronavirus case among Minnesota's team delegation.
In other results, New England Revolution edged Montreal Impact 3-2, FC Cincinnati were 2-1 winners over Columbus Crew, Orlando City and New York City drew 1-1, Atlanta saved a 1-1 draw at Inter Miami, Sporting Kansas City fell 1-0 to Dallas, DC United and Philadelphia Union shared the points in a four-goal clash, Real Salt Lake trumped Portland Timbers 2-1 and Nashville accounted for Houston Dynamo 3-1.
Thomas McNamara's goal in the 88th minute gave New England a 3-2 victory over New York City FC, just three minutes after Ismael Tajouri-Shradi had equalised for the home side.
Gustavo Bou and Jon Bell also found the net for the Revolution, who are five points clear of Orlando City in the Eastern Conference.
Out west, goals four minutes on either side of half-time from Yeimar Gomez and Raul Ruidiaz lifted unbeaten Seattle to a 2-1 win at LA Galaxy.
Orlando City got early goals from Tesho Akindele and Nani before Junior Urso netted in the 84th minute to defeat Toronto FC 3-2.
Columbus Crew got a brace from Gyasi Zardes to beat Chicago Fire 2-0, while Colorado Rapids won by the same scoreline at FC Cincinnati as Diego Rubio and Jonathan Lewis found the scoresheet.
Ola Kamara's 72nd-minute penalty was the difference for D.C. United in a 1-0 win over Inter Miami, who saw Gregore and Ryan Shawcross shown red cards.
Portland Timbers defeated Sporting Kansas City 2-1 on first-half goals from Dairon Asprilla and Marvin Loria.
Ricardo Pepi's 68th-minute equaliser gave FC Dallas a 1-1 draw with Minnesota United after Franco Fragapane had given the visitors a first-half lead, while Austin FC and San Jose Earthquakes finished in a 0-0 draw.
Houston Dynamo earned a point on the road in a 1-1 draw against Los Angeles FC as Maximiliano Urruti matched Jose Cifuentes' second-half goal.
Reynoso scored twice inside the opening 20 minutes to set up the triumph which lifts United up to sixth spot after they had suffered back-to-back defeats.
The Argentine fired in a low left-foot shot to open the scoring in the fourth minute before jinking inside and netting from similar range in the 20th minute to double the lead.
United goalkeeper Tyler Miller saved well to deny Dejan Joveljic prior to half-time, before Ethan Finlay got in behind the Galaxy defence from Franco Frangapane's pass to add a third in the 66th minute.
The result sees Minnesota move up to sixth in the Western Conference with 34 points, while Galaxy stay fourth but are winless from their past six games.
Runaway league leaders New England were held to a 1-1 home draw with Columbus Crew.
Polish attacker Adam Buksa netted a 62nd minute equalizer after US international Gyasi Zardes had put Crew ahead in the 58th minute.
Zardes had missed a gilt-edged header in the 22nd minute but he took his opportunity early in the second half from Harrison Afful's cross.
Buksa levelled, swooping on a poor Jonathan Mensah pass in defence, handing the Pole a sniff on goal which he converted with a left-foot shot.
An injured Eloy Room made two crucial late saves to deny Buksa a winner as the Crew held on.
Struggling Austin slumped to a fifth straight defeat after blowing a 3-1 second-half lead to lose 4-3 to San Jose Earthquakes.
The Earthquakes scored three goals in 14 second-half minutes to complete the comeback headlined by Javier Lopez's double.
New York City firmed up their grip on a playoffs spot after a 2-1 win away to Cincinnati who were reduced to nine men after red cards to Alvaro Barreal and Isaac Atanga.
Damir Kreilach's early second-half goal was enough to get Real Salt Lake past Seattle Sounders 1-0, while Houston Dynamo won 3-2 over Dallas in the Texas derby.
Lowly Toronto ended their six-game losing run with a shock 2-1 home win over Nashville, while Atlanta United secured their third straight triumph with a 3-2 victory over DC United.
Cristian Roldan inspired Seattle to a 3-1 win over the Galaxy in California.
Roldan opened the scoring in the 12th minute, completing a fine team move by getting on the end of a Jordan Morris cross.
Morris doubled the lead seven minutes before half-time, finishing after a lovely pass from Nicolas Lodeiro.
Roldan produced a clinical finish from a Joao Paulo pass to make it 3-0 just after the hour-mark, with Seattle winning despite Sebastian Lletget's late goal for the LA Galaxy.
It marked Roldan's third multi-goal game in MLS, and two have come against the Galaxy.
Seattle are top of the Western Conference, equal on points with the Portland Timbers, who recorded a 1-0 win over the Vancouver Whitecaps.
After joining Inter Miami following his Juventus release, Higuain had a tough debut in a 3-0 loss to the Philadelphia Union.
Higuain hit the outside of the post with a bicycle kick and later put a penalty over the crossbar.
Anthony Fontana, Ilsinho and Brenden Aaronson scored for Philadelphia, who are second in the Eastern Conference.
Higuain, meanwhile, has failed to convert his past four penalties in all competitions.
Eastern Conference leaders Columbus Crew fell to a 3-1 loss to Toronto.
The New York Red Bulls thrashed the Montreal Impact 4-1, the New England Revolution beat DC United 2-0 and Chicago Fire overcame Atlanta United 2-0.
Minnesota United played out a goalless draw with Real Salt Lake, while Dallas' clash with Orlando City also finished 0-0.
The San Jose Earthquakes ended a nine-game winless run by beating Los Angeles FC 2-1.
Alan Pulido, Luis Martins and Daniel Salloi all scored within 16 minutes as KC raced to a 3-0 lead. Salloi's classy volley took his tally to nine goals this MLS season.
Israeli midfielder Gadi Kinda added a fourth in the 58th minute with Graham Zusi getting his second assist, before LAFC got a consolation from Danny Musovski.
The win lifted Sporting KC past Seattle Sounders who conceded in the 90th minute to draw 1-1 at home with Dallas.
Fredy Montero had put the Sounders ahead in the 72nd minute with a set-piece header but Dallas equalised from Franco Jara's 90th-minute close-range strike.
Sporting KC are ahead of Seattle on goal difference, with both sides having 33 points, although the leaders have a game in hand.
LA Galaxy are third following a 1-0 victory over Real Salt Lake, secured by Efrain Alvarez's cool 53rd-minute winner.
Eastern Conference leaders New England extended their unbeaten run to five games with a 0-0 draw against Nashville, who slip to fourth despite the result.
The draw also extends Nashville's undefeated streak to nine games.
Former England international Kieran Gibbs netted a 66th-minute equaliser to earn Inter Miami a 1-1 draw away to fellow Florida outfit Orlando City. The goal was Gibbs' first in the MLS.
Philadelphia Union ended their three-game winless run with a 3-0 victory over Toronto after three first-half strikes.
Ola Kamara and Yordy Reyna both netted doubles as DC United won 4-2 over Columbus Crew.
Tomas Pochettino scored a first-half brace as struggling Austin won 3-2 over Houston Dynamo.
Chicago Fire and 10-man New York City played out a goalless draw, while New York Red Bulls and Cincinnati also ended 0-0 and Portland Timbers drew 1-1 with San Jose Earthquakes.
Sergio Santos netted three times as Philadelphia crushed Toronto 5-0 at Subaru Park on Saturday.
The result equalled the Union's biggest ever win and Toronto's largest defeat, as per Opta.
Philadelphia needed until the 27th minute to get going, Sergio Santos heading in a wonderful cross from Kai Wagner.
Just six minutes later and the hosts doubled their lead, Mark McKenzie heading in from close range after a corner.
Jamiro scored a spectacular third for Eastern Conference leaders Philadelphia in the 56th minute, his 20-yard effort going in off the underside of the crossbar.
Sergio Santos put away two more to complete his hat-trick – the fourth in the Union's history and first since C.J. Sapong in May 2017.
Western Conference leaders Sporting also enjoyed a fine win, thrashing the Colorado Rapids 4-0.
Alan Pulido, Andreu Fontas, Gadi Kinda and Gerso Fernandes netted in the victory.
Leandro Gonzalez Pirez's 89th-minute winner saw Inter Miami – without the suspended Gonzalo Higuain – edge Orlando City 2-1, while DC United overcame Atlanta United 2-1.
New York City recorded a 3-1 victory over the Montreal Impact and the Vancouver Whitecaps were too good for the San Jose Earthquakes 2-1.
The Chicago Fire and New York Red Bulls drew 2-2, Minnesota United edged Cincinnati 1-0, Houston Dynamo and Columbus Crew drew 1-1 and Real Salt Lake and Dallas played out a goalless draw.
Super sub Ruidiaz came off the bench and scored a delightful game-winning goal just past the hour-mark as the Sounders downed Dallas 1-0 in MLS on Wednesday.
The Sounders were winless in 10 consecutive visits to Dallas (D3 L7, including play-offs) dating back to 2014 – their second-longest winless away run against a single opponent in MLS (11 straight at LA Galaxy from 2010 to 2015).
But Seattle snapped that skid thanks to Ruidiaz as Sporting KC's 1-1 draw with Portland Timbers allowed the Sounders to move top of the west by one point.
Atlanta extended their winning streak to three matches after Ezequiel Barco's first-half goal secured a 1-0 win at home to Toronto.
Since the sacking of head coach Gabriel Heinze following a falling out with star Josef Martinez, Atlanta – who had won successive matches for the first time since the opening two games of the 2020 season entering the fixture – have steadily climbed the table.
Atlanta are three points outside of the play-off positions in the Eastern Conference, which is topped by New England Revolution – 3-2 victors against DC United despite ending the contest with 10 men.
Elsewhere, Rodolfo Pizarro's stoppage-time winner guided Inter Miami to a dramatic 3-2 win against Chicago Fire midweek.
Pizarro struck in the 93rd minute to clinch a third straight home triumph for David Beckham's Inter Miami, who have now lost just once in their last six games.
Philadelphia Union and New York Red Bulls were 1-0 winners over New York City and Columbus Crew respectively, Vancouver Whitecaps topped Austin 2-1, Real Salt Lake defeated Houston Dynamo by the same scoreline, 10-man Montreal drew 0-0 with Cincinnati, while Nashville and Orlando City played out a 1-1 draw.
After Raul Ruidiaz's 40th minute opener, the visitors had taken the lead after goals from Cristian Dajome and Lucas Cavallini.
Medranda intervened with his 71st minute strike, coming after a corner was cleared into his path, lashing home from the edge of the box.
The result means Seattle remain top in the Western Conference, having conceded only seven goals in 11 games.
It also ends Vancouver's five-game losing streak, although they remain second last in the west.
Former Manchester United striker Javier 'Chicharito' Hernandez scored a double to lift LA Galaxy to a 3-1 win away to San Jose Earthquakes.
The Mexico international opened the scoring in the 11th minute when he swept home Samuel Grandsir's dangerous cross from the right.
Hernandez produced a similar finish to double their advantage in the 50th minute, tapping home from Kevin Cabral's ball.
Galaxy are third in the Western Conference, four points behind Seattle with a game in hand.
Philadelphia Union extended their unbeaten run to eight games with a 3-3 draw away to Chicago Fire.
Toronto's struggles continued with a 2-0 home defeat to Cincinnati, condemning them to five consecutive defeats.
Sporting Kansas City defeated Los Angeles FC 2-1, Real Salt Lake and Houston Dynamo drew 1-1, Minnesota United won 1-0 at Portland Timbers and Abu Danladi netted a late leveller to help Nashville claim a 1-1 home draw with Montreal.
Cristian Roldan, Jimmy Medranda and Joao Paolo scored in a three-goal first half to inspire the Sounders against the Rapids in Seattle.
The Rapids were enjoying their second-best unbeaten run in club history, only behind the 15-game undefeated streak from April 2016 to July 2016.
But Colorado came unstuck away to the Sounders at Lumen Field, where Roldan broke the deadlock in the second minute before Medranda and Paolo's moment of individual brilliance made it 3-0 prior to half-time.
The Sounders are top of the west, two points clear of Sporting Kansas City, who beat Houston Dynamo 4-2 behind Daniel Salloi's magical performance (one goal and an assist) and Johnny Russell's brace.
Entering the contest, Salloi and Russell had been directly involved, either together or individually, in Sporting KC's previous seven goals (Salloi three goals, Russell three goals and two assists). At least one of those two players had scored or assisted on 19 of the 23 goals Kansas City scored since late July.
David Beckham's Inter Miami and their hopes of featuring in the play-offs were dealt a blow following a 1-0 defeat to Portland Timbers.
Jaroslaw Niezgoda struck to extend Portland's unbeaten run to eight matches, including seven wins, and condemn Inter Miami to a fourth consecutive loss.
Inter Miami are eight points adrift of the post-season places in the Eastern Conference with seven fixtures remaining, while the fourth-placed Timbers are seven points clear of Real Salt Lake in the battle for home-field advantage.
Elsewhere, 10-man Philadelphia Union were 3-0 winners over defending champions Columbus Crew, Toronto defeated Chicago Fire 3-1 and New York City drew 0-0 with Nashville, while the El Trafico derby between LA Galaxy and Los Angeles FC ended 1-1.
Seattle booked their spot in the second round of the play-offs thanks to goals from Jordan Morris, Nico Lodeiro and Raul Ruidiaz on Tuesday, earning a home date with Dallas.
Morris, Lodeiro and Ruidiaz all scored in the same MLS match for the fourth time, more than any other trio of team-mates since the start of the 2018 season, per Opta.
Lodeiro opened the scoring in the 18th minute – Morris teeing up the Uruguayan for a first-time shot past LAFC goalkeeper Pablo Sisniega.
LAFC's star captain Carlos Vela had a penalty saved three minutes later as Sounders goalkeeper Stefan Frei stopped a non-shoot-out spot-kick for the first time since April 2016, after allowing goals on the previous 18 on-target penalties he had faced.
After Morris and Lodeiro hit the woodwork in quick succession, Ruidiaz doubled the lead in the 66th minute before Eduard Atuesta reduced the deficit 11 minutes later.
Morris, though, restored Seattle's two-goal advantage within three minutes as the Sounders moved through to the next round.
Meanwhile, expansion franchise Nashville stunned Toronto 1-0 after extra time to earn an Eastern Conference semi-finals berth.
Daniel Rios' 108th-minute goal settled the contest in Connecticut, where seventh seeds Nashville became the third team in MLS history to win each of their first two play-off matches.
Rios' winner was also the first Toronto has ever conceded in extra time of a MLS play-off clash.
Nashville will now face Columbus Crew for a place in the Conference finals.
In the day's other fixture, New England Revolution shocked Eastern Conference top seeds Philadelphia Union 2-0.
First-half goals from Adam Buksa and Tajon Buchanan set the tone for the Revolution, who are the first team to score multiple goals in an away match against the Union all season.
Next up for Bruce Arena's Revolution are Orlando City.
Roldan struck in the 18th minute for the unbeaten Sounders, who left PayPal Park in San Jose with maximum points on Wednesday.
After the Earthquakes failed to clear their lines, Roldan riffled a thunderous half-volley into the back of the net from outside the penalty area.
The Sounders are now four points clear of the Earthquakes and LA Galaxy, who have played a match less in the west.
David Beckham's Inter Miami – coached by former Manchester United defender and midfielder Phil Neville – suffered a 2-0 defeat at home to Montreal following a 140-minute weather delay.
Bjorn Johnson scored twice in the space of 11 first-half minutes to give visitors Montreal a 2-0 lead inside the opening half an hour in Miami.
The match was then suspended in the 47th minute due to lightning strikes at DRV PNK Stadium, where Montreal held on for victory after more than two hours of waiting.
Montreal top the Eastern Conference, level on eight points with New England Revolution, who played out a 1-1 draw against Philadelphia Union, while Inter Miami have five points from five games.
Elsewhere, Toronto celebrated their first win of the season after topping defending champions Columbus Crew 2-0, Houston Dynamo were 1-0 victors over Sporting Kansas City, while Minnesota United defeated Vancouver Whitecaps by the same scoreline.
Sporting claimed a 2-1 win over Minnesota United at Allianz Field to pull clear atop the Western Conference.
Michael Boxall's 55th-minute own goal proved decisive as Sporting claimed a fifth win in six MLS games, going four points clear of second-placed Minnesota.
Gadi Kinda got on the end of a Jaylin Lindsey cross to give Peter Vermes' Sporting a 12th-minute lead.
Minnesota were level just after the half-hour mark, an unfortunate deflection off Lindsey leading to an own goal.
But Boxall turned a cross into his own net 10 minutes into the second half for what proved to be the winner.
Toronto recorded a second win in four days over the Vancouver Whitecaps with a 1-0 victory.
Richie Laryea's low finish in the 15th minute was all Toronto needed, getting back to within a point of Eastern Conference leaders Columbus Crew.
In the day's other games, Cincinnati and DC United drew 0-0, while the Houston Dynamo's clash with Dallas also finished goalless.
Johnny Russell's 79th-minute goal gave Sporting KC a 2-1 win away to Seattle Sounders, locking up a play-off spot for the second-placed team in the Western Conference table as Russell netted for the seventh straight game.
Colorado also are in after defeating Portland Timbers 2-0 behind golas from Dominique Badji and Diego Rubio.
The Seattle loss ensured New England, who face Orlando City on Sunday, will finish atop the overall table. The Revs are on 69 points, 20 points clear of Philadelphia and Nashville in the Eastern Conference and 11 clear of Seattle overall.
Nashville had a chance to clinch the play-offs with a win but fell 1-0 to Philadelphia Union on Kacper Przybylko's first-half penalty.
Inter Miami got a goal and three assists from Gonzalo Higuain, while his brother Federico also found the net in a 5-1 rout of Cincinnati, who lost their ninth in a row.
Toronto dealt a blow to rival Montreal's play-off hopes as Jozy Altidore's free kick in the fifth minute of stoppage time secured a 1-1 draw after Sunusi Ibrahim had netted in the 55th minute for the visitors.
Minnesota and LAFC also finished at 1-1, as did San Jose Earthquakes and Vancouver Whitecaps.
New York City crushed DC United 6-0 and Sean Nealis' 87th-minute goal lifted New York Red Bulls past Columbus Crew 2-1.
Sebastian Lletget's brilliant 83rd-minute equaliser gave LA Galaxy a 2-2 draw with Dallas, while Chicago Fire downed Real Salt Lake 1-0.