Alejandro Davidovich Fokina insisted he had no regrets despite an ill-advised underarm serve virtually handing victory to Holger Rune in their third-round clash at Wimbledon.
The Spaniard had let an 8-5 lead slip in the deciding first-to-10-point tie-break when, at 8-8, he decided to pull out an underarm serve, which sixth seed Rune easily put away before clinching a 6-3 4-6 3-6 6-4 7-6 (8) win on the next point.
Davidovich Fokina was unrepentant, though, calling the shot simply “another serve”. Asked if he would make the same decision again, he added: “Why not?”
The 24-year-old, who is ranked 34, insisted he would look back on the match positively, saying: “I won’t regret anything.
“I’m happy for this match that I did because I was struggling on grass and how I played today I convinced myself that I have a lot of things in myself.”
It is the third time in his last five matches at Wimbledon that Davidovich Fokina has shot himself in the foot with highly questionable decisions.
In a first-round meeting with Hubert Hurkacz 12 months ago, he was 40-0 up serving for the match in the third set when he tried an unnecessary tweener.
Davidovich Fokina did eventually come through that one in a deciding fifth-set tie-break only to lose to Jiri Vesely in another tie-break in the second round when he smashed a ball out of the court while match point down and was given a point penalty.
Rune has had plenty of dramatic moments in grand slams himself this season and has now played a match tie-break at each event – losing to Andrey Rublev in Australia before beating Francisco Cerundolo in Paris.
He certainly was not complaining about Davidovich Fokina’s moment of madness, saying: “I was not expecting for sure that that was going to come.
“Actually it was nice because he was serving unbelievable so I was like, ‘OK’, it was a chance to get a match point. I had to be fast with the feet. Wow, what a match.”
Rune next faces either Frances Tiafoe or Grigor Dimitrov, who was leading by two sets to love when rain forced an early end to the day’s play on the outside courts.
Van de Zandschulp reached the round of 16 at Wimbledon before losing Rafael Nadal, and he was undone by another Spaniard on the clay in Germany.
Davidovich Fokina broke Van de Zandschulp's serve six times en route to a 6-4 6-4 victory.
He will next face qualifier Jozef Kovalik, who also progressed on Monday alongside Slovakian compatriot Alex Molcan.
Lorenzo Musetti prevailed in three sets against Dusan Lajovic, while Karen Khachanov went the distance in beating Jan-Lennard Struff.
There was a shock at the Swiss Open Gstaad as home wild card Alexander Ritschard knocked out eighth seed Joao Sousa in straight sets.
Fifth seed Pedro Martinez beat fellow Spaniard Carlos Taberner, while there were also wins for Federico Delbonis and Jiri Lehecka.
Carreno Busta fell to a 6-3 1-6 7-6 (7-5) second-round defeat against Slovakian Alex Molcan, who progressed to a fourth ATP Tour quarter-final this season.
World number 48 Molcan will next meet Borna Coric after the Croatian eased past Tallon Griekspoor 6-3 6-4, registering back-to-back tour-levels wins for the first time in 17 months.
Second seed Rublev coasted through his first-round clash with Ricardas Berankis, triumphing 6-3 6-4 as he improved his record at the ATP 500 clay-court event in Germany to 10-2.
"I am happy with my performance. Ricardas is a really tough player," said world number eight Rublev, who is aiming for his fourth title of the season after success in Marseille, Dubai and Belgrade.
"He hits the ball really hard and plays fast, so I had to bring intensity from the first game. I am really happy with how I was serving today and I hit some great shots from the baseline.
"The game he broke me in the second set he played really well. He returned really aggressively and I don’t think I made one first serve. But then I kept [my] focus and broke him straight away again."
Alejandro Davidovich Fokina was another comfortable winner, easing past Jozef Kovalik 6-2 6-2 to set up a quarter-final contest with Lorenzo Musetti, who beat Emil Ruusuvuori 6-4 7-5.
Play was suspended early at the Swiss Open due to bad weather, with Spaniard Jaume Munar downing Alexander Ritschard 6-3 6-3 in the only match of the day to reach the last eight.
That meant top seed Casper Ruud will have to wait until Thursday to face Jiri Lehecka in Gstaad, with third favourite Roberto Bautista Agut also seeing his match with Juan Pablo Varillas pushed back a day.
Kyrgios suffered a disappointing semi-final defeat to Andy Murray in Stuttgart last week, but looked greatly improved against Tsitsipas as he recovered from a set down to win 5-7 6-2 6-4.
It was the second serve of both men where Kyrgios shone, winning 76 per cent (28 of 37) of points on his second serve, and 58 per cent (23 of 40) on his opponent's.
"Stef is one of the best players in the world at the moment and he's going to have some amazing results and I'm sure many, many grand slams," Kyrgios said following his win.
"I don't know if I can say the same for me, but I'm happy to still be able to produce this level with the tournaments I play. It is a testament to how hard I do work when I'm not playing."
He will face Pablo Carreno Busta in the quarter-finals after the Spanish sixth seed beat Sebastian Korda 6-4 0-6 6-3.
Elsewhere, Hubert Hurkacz will face Felix Auger-Aliassime in the last eight after defeating Ugo Humbert 7-6 (7-5) 6-3, while the Canadian also won in straight sets against Mackenzie McDonald 7-6 (9-7) 6-1.
The one remaining first round match saw number one seed Daniil Medvedev beat David Goffin 6-3 6-2 to set up a second round clash with Ilya Ivashka.
At the Queen's Club Championships, sixth seed Denis Shapovalov was eliminated by Tommy Paul 6-4 2-6 6-4, with the American now scheduled to face Stanislas Wawrinka in the second round.
It means that six of the eight seeds in west London were knocked out in the first round, with Matteo Berrettini and Marin Cilic the only remaining seeds. The latter sealed his place in the quarter-finals on Wednesday with a 7-6 (8-6) 7-5 win over Alexander Bublik.
Cilic will play Finland's Emil Ruusuvuori in the last eight after he beat home favourite Jack Draper 6-2 7-6 (7-2).
The best contest of the day came between Alejandro Davidovich Fokina and Alex de Minaur, with the former coming from behind to win 4-6 6-4 7-5 to set up a quarter-final with Botic van de Zandschulp, who beat Grigor Dimitrov 7-6 (7-5) 6-3.
The 2021 US Open champion triumphed 6-3 7-5 over the Spaniard in one hour and 44 minutes, securing his 18th straight victory.
Medvedev will face Frances Tiafoe in the semi-finals after the American beat Briton Cameron Norrie 6-4 6-4 in the other quarter-final in that half of the draw.
The Russian had suffered an ankle injury during Tuesday's last-16 win over Alexander Zverev but played on to clinch a hard-fought three-set win.
But Medvedev alleviated any injury concerns, although he required treatment on a bloody right thumb in the second set while escaping from 0-40 at 3-4.
"I'm actually happy the ankle didn't hurt much because when I warmed up, it was hurting pretty bad," Medvedev said post-match.
"I knew I was going to play, I knew I was going to try. But I couldn't move well on the warm-up. I tried to warm it up as long as possible, took one painkiller so that probably helped. I was actually feeling better and better during the match."
Medvedev raced to a 3-0 lead in the first set and never looked back, although Davidovich Fokina fought hard in the second frame but missed his big chance in the eighth game.
The pair both hit 24 winners for the match, but the Spaniard's 24 unforced errors compared to Medvedev's 12 was a key difference.
Tiafoe, who made last year's US Open last four, awaits after needing only one hour and 25 minutes to eliminate 2021 Indian Wells champion Norrie and reach his maiden ATP Masters 1000 semi-final.
Norrie had been on an eight-match winning run but the American hit 22 winners and only gave up nine unforced errors.
The three-time grand slam champion was largely in control against his Austrian opponent, hitting nine aces and saving all three break points against his serve, while Thiem could only save one of the three he faced as Murray won 6-3 6-4.
He will now play 14th seed Denis Shapovalov after the Canadian beat Ugo Humbert 7-6 (7-1) 6-3.
The winner of that contest will have a last-16 meeting against the victor of Novak Djokovic and Gael Monfils after the latter eased into the round of 32 to set up a clash with the Serbian.
Monfils defeated wildcard Carlos Gimeno Valero 6-3 6-0 in less than an hour, while Alejandro Davidovich Fokina also advanced with a 7-5 6-3 win against Lloyd Harris.
Dusan Lajovic set up a second-round match against fifth seed Casper Ruud, who defeated Borna Coric 6-3 4-6 6-4, and ninth seed Cameron Norrie will go up against John Isner, the Briton having overcome Soonwoo Kwon 7-5 7-5.
An interesting tie awaits the much-talked about Carlos Alcaraz after Nikoloz Basilashvili beat Fabio Fognini 7-5 6-4, with the Georgian to face the number seven seeded teenager next.
Jannik Sinner, the 10th seed, scraped through a hard-fought encounter against American Tommy Paul 6-7 (4-7) 7-6 (7-4) 6-3, and will play Alex de Minaur next after the Australian beat Pedro Martinez 7-6 (7-2) 1-6 6-3.
Diego Schwartzman will take on Grigor Dimitrov in the second round. The Argentine 13th seed beat Benoit Paire 6-2 6-7 (5-7) 6-1, while Dimitrov overcame Maxime Cressy 6-2 7-6 (7-4).
The 7-6 (4) 7-6 (5) 6-2 victory took three hours and 36 minutes, with Djokovic twice a break down in the first set and forced to save a set point in the second.
The 22-time grand-slam champion looked unsettled in windy conditions, while he called the trainer before the third set to have his left thigh massaged, but, as he so often does, he found a way to come out on top.
Djokovic had struggled in his opening set against Marton Fucsovics on Wednesday before breezing through the next two, and it quickly became clear Spaniard Davidovich Fokina would offer a real test.
The 23-year-old, ranked 34, matched his opponent in physical rallies from the baseline and broke for the first time to lead 3-2.
Djokovic hit straight back but was broken again at 5-5 after a game that featured three double faults and a time violation.
Again, Davidovich Fokina was unable to serve it out, though, and Djokovic made him pay for the wasted opportunities by winning a tie-break.
This time the challenge very much continued in the second set as the pair exchanged breaks of serve three times, with Djokovic unable to clinch it at 5-4.
Davidovich Fokina had one chance to break again and level the match in Djokovic’s next service game but he could not take it and the Serbian again came out on top in a tie-break.
Djokovic let his emotions out, roaring and fist-pumping, but the toll the effort had taken became clear when he called the trainer, applying ice to his left thigh and gesturing sarcastically towards the crowd.
Djokovic looked distinctly uncomfortable at times in the third set but he forged ahead early on and did not let Davidovich Fokina back in, giving a weary celebration when the Spaniard’s resistance finally ran out.
“I knew that it’s going to be a very difficult match, a very physical match,” said Djokovic.
“He contested very, very well. He’s an amazing fighter, amazing player. Congratulations to him for fighting. Bad luck but he played a great match.
“Of course a win is a win, maybe a little bit too much, three hours for two sets. I thought, if I would lose the second set, we’d probably play for five hours.
“But you have to be ready. It takes a lot of effort but we all have to believe in ourselves. I’m proud of the performance today for sure.”
It was another day of long matches, with Italian Lorenzo Sonego fighting back from two sets down to defeat seventh seed Andrey Rublev, while Austrian qualifier Sebastian Ofner saw off Fabio Fognini in five sets.
After his epic victory over Stan Wawrinka, Australia’s Thanasi Kokkinakis was involved in another lengthy battle with 11th seed Karen Khachanov but was unable to force a decider, losing out 6-4 6-1 3-6 7-6 (5).
Peniston beat world number five Casper Ruud as he reached the quarter-finals at the Queen's Club Championships last week, and followed that up by recovering from a set down against Rune to reach Eastbourne's last 16 in impressive fashion.
After wrapping up a 4-6 7-6 (7-5) 6-1 win, the 26-year-old told the home crowd: "I'm very happy with that. A tough start but I managed to fight, thanks to you guys.
"Since Queen's it has been madness. A couple of weeks ago was a lot different and things have changed, but I'm loving it."
Rune, who was twice two points from victory in an enthralling contest, was jeered by spectators after hitting a ball out of court and kicking his towel bin after being broken in the third set.
Peniston will face Pedro Martinez in the next round after he benefited from fellow Spaniard Alejandro Davidovich Fokina being forced to retire at one set apiece, while Ugo Humbert fell to a 6-7 (2-7) 6-3 6-4 reverse against Brazil's Thiago Monteiro.
Lorenzo Sonego posted a 4-6 7-6 (7-5) 7-6 (7-1) win over James Duckworth, while Tommy Paul recovered from a set down to beat Francisco Cerundolo and home favourite Dan Evans overcame Adrian Mannarino 6-4 6-3.
The seeds in action at the Mallorca Open endured mixed fortunes as Sebastian Baez cruised past Jordan Thompson in straight sets, but Botic van de Zandschulp was beaten by Marcos Giron.
The Dutchman succumbed to a 6-7 (6-8) 6-4 7-6 (7-2) defeat, while Germany's Daniel Altmaier beat Dusan Lajovic 7-5 7-6 (7-2).
Nick Kyrgios set up an enticing last-16 meeting with fifth seed Roberto Bautista Agut by knocking out Serbia's Laslo Djere in a marathon three-set contest, recovering to win 5-7 7-6 (7-1) 7-6 (7-1).
Andrey Rublev was a surprise first-round loser at the Halle Open, while numerous seeds fell on the first day of the Queen's Club Championships.
Rublev came unstuck against Georgian Nikoloz Basilashvili, succumbing to a 7-6 (7-1) 6-4 loss as the world number eight crashed out in Germany.
Laslo Djere progressed after Henri Squire retired when 4-3 down, while sixth seed Pablo Carreno Busta secured a 6-3 7-6 (7-5) over French Open quarter-finalist Holger Rune.
Ugo Humber got the better of a topsy-turvy affair against qualifier Radu Albot, eventually triumphing 6-7 (4-7) 7-6 (7-4) 7-5 and Mackenzie McDonald defeated Marc-Andrea Huesler in straight sets.
Fourth favourite Taylor Fritz went down 6-3 6-3 against British wildcard Jack Draper, his first career win against a top-20 ranked player.
Reilly Opelka, the eighth seed, crashed out in the first round to New Zealand's Alex de Minaur, who claimed a straightforward 6-4 6-4 win.
Grigor Dimitrov, who won the event in 2014, battled past third seed Cameron Norrie 6-7 (2-7) 6-1 6-4, while Spaniard Alejandro Davidovich Fokina eased past compatriot Albert Ramos-Vinolas 7-5 6-4.
Alexander Bublik was 6-3 up before Italian Lorenzo Musetti retired, while seventh seed Marin Cilic capped the day's play in London by beating home hope Liam Broady 6-1 4-6 7-5.
The number two seed got off to a rocky start, finding himself 5-2 down in the first set before dramatically turning the tide, winning five straight games.
Rublev's first serve percentage improved from 49 to 58 in the second set as he stepped up his game against his Serbian opponent.
"Filip is one of my good friends, and we always have tough battles," Rublev said after his win. "So, today I was going on court thinking that it was going to be a really tough match, and when he started the way he did, I didn't know what to do because he was playing so good.
"Somehow I calmed myself and said 'OK, restart at the bottom and raise my level', and I started to play much, much better. I was able to turn the match around and finish the match in a good way."
He will face Alejandro Davidovich Fokina in the second round after the Spaniard took just 52 minutes to beat Malek Jaziri 6-2 6-0, converting all five of his break points as he strolled to victory.
Seventh seed Alexander Zverev had to come from behind to beat Jiri Lehecka 4-6 6-3 6-4, while Tallon Griekspoor set up a second-round clash with top seed Novak Djokovic after the Dutchman beat Constant Lestienne 6-4 3-6 6-2.
The world number three and top seed had no answer to an impressive performance from Rune, with the young Dane ultimately easing to a 6-3 6-2 victory on Wednesday.
Rune set the tempo early on, moving Zverev around the court with plenty of drop shots and heading into a 4-2 lead, before saving two break points on his way to clinching the first set.
An early break in the second then seemed to give the 18-year-old the confidence to see out his first career victory against a top 10 opponent.
"It was a difficult match from the beginning," said Rune on-court after the win. "He's in the top three in the world and has been playing some unbelievable tennis, especially in the past year winning so many big titles.
"I have a lot of respect for him, and I obviously didn't expect to win in two sets, and with a score like this. But it was a really hard match, we played a lot of rallies and I'm really happy about my performance today."
Rune will play Emil Ruusuvuori in the quarter-finals after the Finn beat Maxime Cressy 6-3 6-3.
Elsewhere, fourth seed Nikoloz Basilashvili came from behind to overcome Ilya Ivashka 3-6 6-2 6-4, and will face Miomir Kecmanovic in the last eight after the seventh seed beat Daniel Altmaier 6-2 6-4.
There were also three round of 32 matches on Wednesday, with eighth seed Botic van de Zandschulp, Egor Gerasimov and Alejandro Tabilo all through to the last 16 in Munich.
Over at the Estoril Open, Alejandro Davidovich Fokina will play Frances Tiafoe in the quarter-finals after both advanced in Portugal.
Fourth seed Davidovich Fokina beat fellow Spaniard Bernabe Zapata Miralles 6-3 7-6 (7-5) while fifth seed Tiafoe got the better of Nuno Borges 7-6 (7-4) 4-6 6-0.
Fernando Verdasco is also through after a 6-2 6-3 win against Pablo Cuevas, and he will play fellow Spaniard and sixth seed Albert Ramos-Vinolas, who came from a set down against Kwon Soon-woo, 5-7 6-1 6-2.
The number one seed dominated his Argentine opponent from the moment the first set went to 3-3, winning nine-straight games from there to ease to victory.
Ruud did need to save four break points in the second game of the second set, but his ability to hold serve seemed to end any resistance that Baez could muster.
The Norwegian will face Frenchman Quentin Halys in the semi-finals after his own straight-sets triumph over Dominic Thiem
Halys reached his first ever ATP Tour semi after recording a 6-1 6-4 win over the former world number three in just one hour and 19 minutes.
The other semi-final will see Miomir Kecmanovic take on Marco Cecchinato after the latter stunned third seed Alejandro Davidovich Fokina in straight sets.
The world number 96 claimed a 7-5 7-6 (7-5) victory in the first meeting between the pair to set up a last-four clash with Kecmanovic, who saw off sixth seed Bernabe Zapata Miralles with a comfortable 7-5 6-2 win.
Elsewhere, Dan Evans is the only seed remaining in the Grand Prix Hassan II as he reached the semi-finals by cruising to a 6-3 7-5 triumph over world number 201 Andrea Vavassori in Marrakech.
Evans will face Roberto Carballes Baena next after the Spaniard toppled fourth seed Tallon Griekspoor 6-3 2-6 6-2.
Second seed Lorenzo Musetti was beaten by Alexandre Muller 6-3 1-6 6-4 in a topsy-turvy encounter, and the Frenchman will now face Pavel Kotov in the final four after the Russian defeated Christopher O'Connell in a thriller, 6-3 6-7 (6-8) 7-6 (7-3).
The Norwegian prevailed 7-6 (7-5), 1-6, 6-3, 4-6, 6-3 in an instant classic that lasted just over four hours on Court Suzanne Lenglen.
Ruud knew he was in for a tough match after winning the tiebreak in the first set, and Davidovich Fokina fought back in brilliant fashion to take the second.
The momentum swung back in Ruud’s favour in the third as he regained the lead in the match, but the Spaniard ensured they could not be separated as he forced a decider after another tight contest.
Despite putting up a good fight, Davidovich Fokina failed to see out what would have been a stunning win, as Ruud edged one step closer to a potential first Roland Garros title.
Next up for Ruud is Tomas Martin Etcheverry in the third round.
Data Debrief: Ruud holds his nerve
Ruud lost his first-ever Roland Garros second-round match (v Albert Ramos in 2018) but is unbeaten in his six matches at that stage of the French Open since.
The Norwegian has now reached the third round at Roland Garros six times in his career, which is more than he has in all other three Grand Slams combined (two at the Australian Open, two at the US Open, 0 at Wimbledon).
World number 12 Sinner, the 11th seed in the French capital this week, suffered a straight-sets loss to Marc-Andrea Huesler, as did 15th favourite Cilic against Lorenzo Musetti.
Ninth seed Fritz downed Alejandro Davidovich Fokina 7-5 6-2, with Cameron Norrie and Frances Tiafoe also recording straight-sets victories against Miomir Kecmanovic and Lorenzo Sonego respectively.
Victory for Fritz kept the American in the hunt for qualifying for November's ATP Finals in Turin for the first time, needing to reach the final in Paris to overtake Felix Auger-Aliassime or Andrey Rublev.
"Right now I'm just focused on kind of playing myself into the tournament," said Fritz. "I feel like any time this year that I've won a couple of matches in a tournament, then I've done well.
"So I'll just try to focus on these early rounds. Turin is still in the picture, obviously, but there's not much else I really could have done.
"Felix has played really, really well, so he deserves it, but I am going to try to steal his spot this week for sure."
Home favourite Gilles Simon awaits Fritz in the second round at the ATP 1000 event after defeating Andy Murray 4-6 7-5 6-3.
Alexander Bublik and Mikael Ymer played out another three-set battle, with the former triumphing 6-1 6-7 (2-7) 6-4.
Richard Gasquet, Yoshihito Nishioka, Karen Khachanov, Maxime Cressy, Nikoloz Basilashvili and John Isner were the other first-round winners on the opening day in France.
Alcaraz was in control, winning the first set in 36 minutes before racing to a 2-0 lead inside 10 minutes before the Briton withdrew. Draper had battled the injury in the latter stages of Monday's win over Andy Murray.
Despite that, the Spaniard looked in good touch, setting up a quarter-final meeting with eighth seed Felix Auger-Aliassime, who has a 3-0 head-to-head record against him.
"I felt the ball really well. I'm really happy with that part," Alcaraz said. "I would say I returned well, I hit great shots. I finished the match with confidence in my shots, to come into the next round with more confidence."
Auger-Aliassime saved six match points in a dramatic triumph over 17th seed Tommy Paul to reach the last eight, winning 3-6 6-3 7-6 (8-6) in two hours and 48 minutes.
The Canadian trailed 0-40 on serve at 5-6 in the deciding set before winning the next five points. He repeated that feat, down 3-6 in the tie-break, capitalising on his first match point. Auger-Aliassime hit 31 winners for the match, along with 51 unforced errors.
Fifth seed Daniil Medvedev fought back from a set down and a rolled ankle to progress past Alexander Zverev 6-7 (5-7) 7-6 (7-5) 7-5 in three hours and 10 minutes.
Medvedev rolled his ankle in the sixth game of the second set, going down in pain but played on, in his longest-ever three-set match. The victory is the Russian's 17th in a row. Zverev committed 50 unforced errors across the match.
The Russian will take on Alejandro Davidovich Fokina in the last eight, with the Spaniard winning 6-3 6-4 over Chilean qualifier Cristian Garin.
Jannik Sinner cruised past Stanislas Wawrinka 6-1 6-4 in one hour and 39 minutes to move into the last eight where he will face reigning champion Taylor Fritz. The American won 6-4 6-3 over Hungary's Martin Fucsovics in one hour and 41 minutes.
British 10th seed Cameron Norrie will play 14th seed Frances Tiafoe in the other quarter-final, with the former winning 6-2 6-4 over the higher-ranked Andrey Rublev. Tiafoe won 6-4 6-4 over Alejandro Tabilo in 83 minutes for his 150th career win.
Auger-Aliassime won just 50 per cent of points behind his first serve as Korda claimed an impressive 6-2 6-2 success over the Canadian in one hour and 29 minutes.
In the semi-finals Korda will take on fellow American Frances Tiafoe, who edged out Alejandro Davidovich Fokina 7-6 (7-5) 5-7 7-5 in a tight encounter.
The other last-four clash will see Albert Ramos Vinolas take on Sebastian Baez.
Ramos Vinolas bested Fernando Verdasco 6-2 6-2 to set up his meeting with Baez after the Argentine rallied from a set down to defeat Richard Gasquet 3-6 6-1 6-4.
At the BMW Open, second seed Ruud fell to Botic van de Zandschulp in the quarter-finals.
The Dutchman won their only previous encounter en route to the last eight at last year's US Open and he triumphed 7-5 6-1 in Munich.
"Maybe the score is easier than it really was," said Van de Zandschulp. "The first set [was] really tight, I think. A great battle in the first one. I had some opportunities to break him in the beginning and didn't take them. Gladly [at] five-all I made the break and held the serve at 6-5.
"[The] second set was a little bit easier, but I think I played really well today."
Next up for Van de Zandschulp is Miomir Kecmanovic, who defeated Nikoloz Basilashvili 7-6 (7-5) 6-2. Holger Rune will continue his impressive run against Oscar Otte in the other semi-final after they overcame Emil Ruusuvuori and Alejandro Tabilo respectively.
Greek Tsitsipas, who defeated Andrey Rublev to triumph in Monaco last year, eased past second seed Alexander Zverev in the semi-final and repeated the trick with a 6-3 7-6 (7-3) victory over Davidovich Fokina.
The Spaniard beat Novak Djokovic and reigning Indian Wells Masters champion Taylor Fritz en route to his maiden ATP Tour final, and started well on Court Rainier III with an early break.
However, Tsitsipas found his rhythm with his ferocious forehand to break back before winning four of the next five games to take the lead.
The world number five, appearing in his fourth Masters 1000 final, then failed to serve out for the match at 5-4 up in the second set, but recovered in the tie-break to secure his first trophy of the season.
In doing so, Tsitsipas becomes the sixth player to manage consecutive Monte Carlo titles in the Open Era, while half of his eight tour-level titles have come on clay.
"I am very proud of myself," Tsitsipas said in his on-court interview. "Things weren't going well at one point, but I managed to stay composed to finish the match off.
"I am really proud with the belief I put in my game. Sometimes you doubt yourself, but it is always important to keep your head high."
Davidovich Fokina was aiming to become the first unseeded champion in Monte Carlo since Thomas Muster in 1992, and Tsitsipas acknowledged the 22-year-old made him fight to reclaim the trophy.
"He fought in moments I didn't expect him to fight," Tsitsipas said. "He can hit incredible winners out of nowhere and play unpredictably.
"But I was able to minimise that. I knew he would be a dangerous opponent but that is a great win for me. I think we will see great results from him in the future."
The third seed, who defeated Andrey Rublev to clinch the title in Monaco last year, produced a scintillating performance to beat the world number three 6-4 6-2 in Saturday's last-four encounter.
Tsitsipas will face world number 46 Alejandro Davidovich Fokina in Sunday's final, and the Greek said he will need to perform at an even higher level to defeat the 22-year-old, whose incredible run continued with a three-set win over Grigor Dimitrov in the final four.
"It was good," Tstispas told Amazon Prime Video of his semi-final win. "I don't know whether the long match [his three-set quarter-final win over Diego Schwartzman on Friday] gave me some rhythm, but I was able to play good tennis today. I'm happy with the level I was able to execute, and I came up with some good ideas on the court.
"I'm looking forward to the next one, I have a difficult opponent tomorrow, so I need to be ready and to take the best out of this one and move on.
"It's going to take a little bit more [to beat Davidovich Fokina], he's in a good rhythm. I've played him before, and he's a difficult opponent, I'm going to be as ready as possible, he's definitely improved and I'm going to have to produce the best tennis I can."
Davidovich Fokina, who has made headlines by eliminating Novak Djokovic and Indian Wells Masters champion Taylor Fritz during a thrilling run in the municipality, beat Dimitrov 6-4 6-7 (2-7) 6-3 earlier on Saturday, reaching his first ATP Tour final.
The unseeded Spaniard needed two hours and 43 minutes to wrap up his semi-final contest, and revealed that a bathroom break allowed him to reset his mind and clinch a hard-fought victory after he failed to serve out the second set at 5-4 up.
"I am so happy to be in the final, it's a dream come true to try to have the title," he said after the win.
"When I was a kid, I was dreaming about this day and it's come true, I'm so happy.
"In the second set I had my chances, I was so tight. But I went to the bathroom [after the second set] and I said to myself 'I want this'. Now I am in the final, I will enjoy, I have all the power with me."
The seventh seed, who was a semi-finalist at the All England Club last year, promised on the eve of the championships to donate €100 in aid for every one of his aces.
"Hope my serve works well," Hurkacz wrote on Twitter, and it certainly did across five sets against Alejandro Davidovich Fokina.
Having averaged 11.6 aces per match this season – his 452 the third most on the ATP Tour – Hurkacz had 21 to just three double faults in an effective serving display on Monday.
Unfortunately, Davidovich Fokina was still able to pull off an early upset, narrowly advancing 7-6 (7-4) 6-4 5-7 2-6 7-6 (10-8).
This was the third top-10 win of Davidovich Fokina's career but the first on grass, with his previous two such victories both coming at the Monte-Carlo Masters (vs Matteo Berrettini in 2021 and versus Novak Djokovic in 2022).
While Hurkacz will not add to his ace tally, John Isner undoubtedly will.
He had a remarkable 54 in his five-set win against Enzo Couacaud – as many as Hurkacz managed across six matches in his 2021 run to the last four.
The last player to record 50 or more aces in a grand slam match had also been Isner, against Steven Johnson at the 2020 US Open.
Last year's runner-up Andrey Rublev, however, missed out on a last-eight spot after falling to a three-set defeat against Jannik Sinner.
World number three Zverev overcame Spain's Pablo Carreno Busta 6-2 7-5 to progress in Monaco, where he is seeking to win the sixth ATP 1000 title of his career.
"For the second clay-court match of the season, I can't complain too much," the 24-year-old second seed said on court after sealing the victory.
"Yes, I lost focus a little bit in the second set, but at the end of the day, he's somebody that can really play. I'm happy with a two-set win."
Tsitsipas (3) remains in contention for a second consecutive title in the principality after defeating Laslo Dere 7-5 7-6 (7-1) and will face off against 12th seed Diego Schwartzman for a semi-final spot after the Argentine defeated Lorenzo Musetti in a hard-fought three-set encounter.
There will be no repeat of 2021's final between Tsitsipas and Rublev, however, after the Russian fell to a thrilling 5-7 6-1 6-3 loss to ninth seed Sinner in the day's final contest.
The other seed to fall victim to a shock in the last 16 was world number seven Casper Ruud, losing 6-3 7-5 to Grigor Dimitrov, who will face Poland's Hubert Hurkacz in the last eight.
Finally, Novak Djokovic's conqueror Alejandro Davidovich Fokina cruised past David Goffin 6-4 6-1 to set up a quarter-final tie with the United States' Taylor Fritz, who bested compatriot Sebastian Korda – with whom he played doubles with in Monte Carlo – in straight sets.
