Runner-up to Iga Swiatek at Roland-Garros two years ago, the third seed recovered from losing her first set of the tournament to prevail 4-6 6-2 6-3 in just under two hours.
Gauff was a dominant 6-0 6-1 winner when she last met Jabeur at the 2023 WTA Finals, while also prevailing 6-3 6-1 in their 2021 French Open encounter.
However, it was the Tunisian - appearing in her second successive quarter-final at Roland-Garros - who struck first, breaking in game seven to move halfway towards a maiden semi-final at the clay-court major.
Gauff hit back with a vengeance and broke her opponent in three successive games to take the contest the distance on Chatrier.
The deciding set swung firmly in the American's favour when she broke to 30 in game during a hot streak in which she won 12 out of 15 points, before holding her own serve to prevail when Jabeur sent a forehand smash wide.
Data Debrief: Gauff matches Evert
Gauff continues to excel at the French Open, where her tally of 20 women's singles match wins before turning 21 is only bettered by Iga Swiatek (21), who she may face in the semi-finals.
Aged 20 years and 82 days old, she is the youngest woman to reach three or more successive major semi-finals since Maria Sharapova's run of four between 2006 and 2007.
Gauff is also the third American women in the Open Era to reach multiple French Open semi-finals before the age of 21, matching the great Chris Evert and Andrea Jaeger.
As for her opponent, Jabeur is the second woman to lose successive completed Roland-Garros quarter-finals after winning the opening set, after Conchita Martinez (1992 and 1993).
Having already recorded her best tour-level run on grass by reaching the final eight, Gauff recorded a superb 7-5 6-4 win over two-time grand slam finalist Pliskova.
Gauff – who reached her first grand slam final at Roland Garros last month, saved four set points in the opener before roaring to victory in one hour and 37 minutes, and was delighted to have overcome a tough opponent in the world number seven.
"I'm super happy with how I played today," Gauff said on court after the win. "Playing her on grass, with her serve, how flat she hits the ball, it was really tough to be honest.
"A first semi-final on grass is pretty cool, and also I feel like the opponents I've played this week haven’t been easy, especially today, so I'm proud of myself about that."
Gauff will face Jabeur for a spot in the final after the Tunisian fought back from one set down in a 6-7 (3-7) 6-2 6-2 win over Aliaksandra Sasnovich, who entered the contest having won 26 matches during an impressive year.
The other semi-final will see Maria Sakkari face Belinda Bencic, after the world number six cruised to a 6-0 6-3 win over Daria Kasatkina and Bencic beat Veronika Kudermetova 3-6 6-3 6-3.
In the Birmingham Classic, meanwhile, Simona Halep raced to a 6-4 6-1 win over Katie Boulter to reach the final four, but third seed Camila Giorgi fell to a 6-3 6-2 loss to Brazil's Beatriz Haddad Maia, who has now won eight consecutive games on grass.
While that pair will face off in one of Saturday's semi-finals, eighth seed Zhang Shuai will face Sorana Cirstea in the other. Zhang overcame Dayana Yastremska 7-5 6-4 and sixth seed Cirstea beat Donna Vekic 5-7 6-3 6-4.
Gauff beat Kovinic 6-0 6-2 to move into her first hard-court final since claiming the title in Linz back in October 2019.
The top seed from the United States won the first eight games of a one-sided semi-final, making another statement just over a week before the Australian Open gets under way.
Gauff took only 73 minutes to dispatch seventh seed Kovinic and will face qualifier Rebeka Masarova in the final on Sunday.
Spaniard Masarova reached her first WTA Tour final courtesy of a 6-3 6-3 victory over Ysaline Bonaventure.
The 130-ranked Masarova, a junior French Open singles champion in 2016, served with assurance and struck 16 winners to break new ground.
It was also a memorable Saturday for Czech teenager Noskova, who claimed the scalp of world number two Jabeur with a 6-3 1-6 6-3 victory in Adelaide.
It was the 18-year-old Noskova's second win over a top-10 opponent this week, having also knocked out Daria Kasatkina.
Second seed Sabalenka will be a strong favourite to deny world number 102 Noskova the title on Sunday after she saw off Irina-Camelia Begu 6-3 6-2.
Second seed Badosa had no answer to the brilliance of Halep in her homeland as the relentless Romanian won 6-3 6-1 at the Caja Magica.
Unseeded two-time grand slam champion Halep took just an hour and 17 minutes to eliminate Badosa, breaking three times in the first set and twice in the second.
Halep, in a new era with Patrick Mouratoglou in her corner, won 84 per cent of points when she landed her first serve in, staying in the hunt to win this tournament for a third time with the French Open on the horizon.
The former world number one will face Coco Gauff for a place in the quarter-finals following the American's 6-1 2-6 6-4 late-night defeat of Yulia Putintseva.
Gauff, the 14th seed, racked up 10 double faults and was pushed all the way by Putintseva, but served out the match after securing a third break in a tight final set.
Ons Jabeur earlier advanced into the third round at the expense of Varvara Gracheva, recovering from a second-set bagel to win 7-5 0-6 6-4.
Jabeur faces a meeting with Belinda Bencic after the Swiss dispatched Karolina Muchova 6-3 4-6 7-5.
Victoria Azarenka came from a set down to beat Tamara Zidansek 3-6 6-1 6-3 to set up a meeting with Amanda Anisimova, who also had to come from behind to dispatch Petra Martic 3-6 6-3 6-2.
Ekaterina Alexandrova and Marie Bouzkova also progressed in the Spanish capital.
A new name will on the Venus Rosewater Dish after the Centre Court showpiece as last year’s runner-up takes on the first unseeded women’s finalist in SW19 since 1963.
Elsewhere, Neal Skupski is going for a Wimbledon hat-trick and the schedule is playing catch up as play was washed out on the outside courts on Friday.
Here, the PA news agency takes a look at day 13.
Ons the way to redemption
Ons Jabeur is back in the Wimbledon final 12 months after she suffered a heartbreaking defeat to Elena Rybakina.
The Tunisian has said that 2022 was never her time, but there is a real sense she is now ready to become a grand slam champion.
She has looked every inch the title contender throughout the tournament with her all-round game and fighting spirit getting her this far.
If she can go one better than last year then she will become the first female singles winner of a grand slam from an Arab or African country.
Vondrousova’s road to recovery
Marketa Vondrousova is also on the path to redemption after injury stalled her promising career.
After reaching the French Open as a teenager in 2019, she has suffered with health issues and revealed that her only participation in Wimbledon last year was watching her best friend in qualification at Roehampton while wearing a cast on her left wrist.
But 12 months on she is in the final after going under the radar until ending Elina Svitolina’s emotional run in the last four.
She will have extra support in her box as her husband has found a cat sitter so is travelling over for the match.
And if she wins, she will become the first unseeded women’s title winner in Wimbledon history.
Skupski going for the hat-trick
Not since Dorothy Round in 1937 has a British player won a hat-trick of Wimbledon titles, but Neal Skupski could be about to emulate that achievement.
The Liverpudlian won the mixed doubles in 2021 and 2022 and is now going for the “pinnacle” in the men’s doubles with Dutch partner Wesley Koolhof.
Skupski will not have his brother and coach Ken in his box as he went on a family holiday to Ibiza on Friday, but he did provide tactical analysis via video.
Marcel Granollers and Horacio Zeballos, who beat Skupski and Koolhof at the French Open, stand in the way.
Order of play
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Centre Court
Marketa Vondrousova v Ons Jabeur
Wesley Koolhof/Neal Skupski v Marcel Granollers/Horacio Zeballos
Court One
Alfie Hewett v Martin De La Puente
Wozniacki/Black v Radwanska/O’Brien
Hewett/Reid v Miki/Oda
Weather
Very strong winds, with the chance of early showers.
Jabeur saw off Ann Li and Evgeniya Rodina in straight sets to reach the last eight, but Liu – ranked 73 in the world – came out on top 6-3 4-6 6-4.
Liu is now into her second semi-final of the season and will face Elise Mertens, who defeated Moyuka Uchijima 6-0 3-6 6-4 in the final match of the day.
Second and third seeds Veronika Kudermetova and Alize Cornet will meet in the other semi after beating Diane Parry and Tamara Zidansek respectively in straight sets.
At the Ostrava Open, meanwhile, tournament favourite Iga Swiatek reached her 10th semi-final of the year with a 6-4 6-4 victory over qualifier Caty McNally.
Swiatek needed nearly two hours to seal her 59th victory of the season – just one short of tying Caroline Wozniacki, the most recent female to hit 60 wins in a calendar year (2017).
She will now face Ekaterina Alexandrova, who proved too strong for Tereza Martincova in a 6-1 4-6 6-1 victory.
Another grand slam winner in Barbora Krejcikova earlier beat Alycia Parks 7-6 (9-7) 6-3 on home soil to maintain her positive form, a week after triumphing at the Tallinn Open.
Awaiting her in the semi-finals is Elena Rybakina following the reigning Wimbledon champion's 7-6 (7-5) 6-4 victory against Petra Kvitova.
Czech player Marie Bouzkova and Spaniard Sara Sorribes Tormo provided stiff competition but eventually succumbed 2-6 6-3 13-11 as Williams grew in belief.
This was the first competitive match for 40-year-old Williams since abandoning her Wimbledon first-round clash against Aliaksandra Sasnovich last June, due to an ankle injury.
It was also her first doubles main-draw match on grass since she and sister Venus won the 2016 Wimbledon title, so she was understandably rusty in the early stages, while world number three Jabeur's nervousness about playing with Williams, which she spoke of after the match, was also evident.
Williams will be on a wildcard at Wimbledon next week, due to her ranking plummeting, as she chases what would be a record-equalling 24th grand slam singles title.
Her game looked sketchy early on, with a smash into the net handing over the second game, before she then blazed a volley over the baseline to concede the early break.
Her own serve was broken as Sorribes Tormo and Bouzkova snatched a 4-1 double-break lead in the opener, which they soon wrapped up.
Williams lost her footing on the grass midway through the second set, slipping over, but she was soon back up, with the contest becoming increasingly competitive.
Jabeur and Williams forged a 4-3 lead in the second set and then broke to force the match tie-break.
All-out assault from Williams brought up a first match point, but the American then rattled a backhand long after Jabeur failed to put away a volley at the net early in the rally.
Another match point slipped away as Jabeur netted from another great chance, but a drop shot from the Tunisian brought up a third, and this time Sorribes Tormo volleyed wide to herald a scream of delight from Williams.
"Oh my god, it was so fun to play with Ons," said Williams. "Our opponents played amazing. They played so well in that first set, they were jamming.
"We were just trying to stay in there after the first set, it was good though.
"I caught some fire behind me, so that's good; I needed that."
Poland’s Swiatek confirmed her position with a 6-1 6-2 win over world number six Ons Jabeur.
Earlier, Gauff claimed a victory for US tennis fans in a battle of two of the major champions from this year.
She defeated Marketa Vondrousova 5-7 7-6 (4) 6-3 in the final round of group play on Friday night, ending the Czech player’s chances of advancing to the semi-finals.
The win was another feather in the cap for Gauff, making her the first teenager to make the final four of the year-end championships since Caroline Wozniacki in 2009.
She will now face Jessica Pegula while Swiatek takes on Aryna Sabalenka.
The Tunisian overcame Australia's Ajla Tomljanovic in a 6-4 7-6 (7-4) victory at Arthur Ashe Stadium, before the Frenchwoman swept aside home favourite Coco Gauff 6-3 6-4.
In doing so, both have reached their first last-four appearance at the final grand slam of the year, and set themselves new benchmarks in the process.
Jabeur is the first Arab or African woman in the Open Era to make the semi-finals at Flushing Meadows.
On the back of reaching the final at Wimbledon earlier this year, she could finish the tournament as the world number two.
Garcia, meanwhile, has reached her first major semi-final without dropping a set along the way.
She has lost just 27 games en route and victory over Gauff extended her winning streak to 13.
In addition, she becomes just the third Frenchwoman to reach the US Open semi-finals in the Open Era, after Amelie Mauresmo and Mary Pierce.
World number four Jabeur, who will team up with Serena Williams at the Eastbourne International, suffered a shock first-round exit at the French Open, but the Tunisian showed no signs of that defeat having affected her in her first grass-court appearance of the season.
Top seed Jabeur required just 73 minutes to overcome Karolina Muchova 6-3 6-3 on Tuesday, with American qualifier Alycia Parks next up after she defeated Qinwen Zheng in straight sets.
Second seed Sakkari, meanwhile, had a similarly comfortable start to her campaign, beating Leolia Jeanjean 6-3 6-2.
Meanwhile, reigning champion Liudmila Samsonova took her place in round two with a 7-5 6-1 victory over Tamara Zidansek.
Samsonova beat Belinda Bencic to claim the title in 2021, and the pair will meet again the quarter-finals should they win respective second-round ties against Veronika Kudermetova and Anna Kalinskaya.
But Kudermetova goes into her clash with Samsonova on a high, having eliminated third seed Sabalenka in a 2-6 7-5 6-4 comeback victory.
WTA Finals champion Muguruza will not be in round two after the Spaniard fell foul of Germany's Andrea Petkovic, who prevailed 7-6 (10-8) 6-4.
"I really do believe that in these really close matches, the simple and little shift of energy can make the difference," Petkovic said.
"If you have the crowd on your side, and they are willing you to the win somehow, I think that can really make a difference."
At the Birmingham Classic, top seed Jelena Ostapenko booked a second-round meeting with Dayana Yastremska.
While Yastremska beat Magda Linette in straight sets, Ostapenko was made to work, with the Latvian requiring two hours to overcome Canada's Rebecca Marino 6-2 5-7 6-3.
Fourth seed Elise Mertens was ditched out by Caty McNally, while former world number two and two-time major champion Petra Kvitova lost to Beatriz Haddad Maia.
Camila Giorgi, the third seed, leads Tereza Martincova after claiming a close first set 9-7 in the tie-break before the match was suspended.
Jabeur, 28, enjoyed the best campaign of her career in 2022 as she reached the finals of Wimbledon and the US Open, but she was sidelined due to knee trouble following this year's Australian Open.
The Tunisian returned with early exits at both the Indian Wells Open and Miami Open, meaning she came into Charleston without consecutive wins since early January.
But she looked right back to her best at the WTA 500 event, not dropping a set the entire tournament.
After beating Lesia Tsurenko, Caroline Dolehide, Anna Kalinskaya and Daria Kasatkina to reach the final, Jabeur had to respond to early adversity against Bencic as the Swiss secured a break in the opening game of the first set.
Down 5-4 in the opener, Jabeur broke back at the last opportunity to keep the set alive, and after falling 6-4 behind in the tie-break she rattled off the next four points in a row to steal it.
The second set was all about making the most of her chances, as Jabeur only had three break-point chances compared to Bencic's five, but she was able to convert all three while Bencic could only snag two.
The final was a rematch from last year's Charleston Open title match, where Bencic prevailed over Jabeur in three sets, and it is Jabeur's first title since the German Open in June, where she again had to overcome Bencic in the final.
Jabeur now leads their head-to-head 3-2 in matches played at WTA Tour level.
The Tunisian world number two won the first set of Sunday's title match but then faded and slid to a 3-6 6-2 6-2 defeat.
Russian-born Rybakina, who switched nationality to Kazakh four years ago after being offered financial incentives to do so, was able to celebrate a surprise maiden slam title.
Jabeur was disappointed after the loss and told reporters in a news conference: "I couldn't do more, I really tried deep inside everything that I can.
"I did everything since the beginning of the year to really focus on this tournament, I even have the trophy picture on my phone.
"It wasn't meant to be. I cannot force things. I'm not ready for it probably, to be a grand slam champion."
The 27-year-old was optimistic of her chances of eventually making a breakthrough at the highest level, and perhaps a chance will come at the US Open in September.
She said: "I cannot wait to look forward to the next one.
"If I have another final I will learn more from it. I cannot wait to really improve a lot of things in my game.
"I want to [continue to] be a top-five player, I want to win more titles, I want to win a grand slam."
Ons Jabeur eased past Camila Osorio in straight sets to progress to the next round of the Nottingham Open.
The three-time grand slam champion returned to the East Midlands for the first team since 2014, and got her grass court season off to a winning start with a 6-2 6-3 win over the Colombian.
It was the perfect start for the world number 10, who earned a break point in the opening game before going on to win the first set, but the Tunisian was made to work to secure her triumph.
Osorio matched Jabeur early on, but the top seed at the tournament showcased her class to come through the encounter, building on her quarter-final run at the French Open as her preparations for Wimbledon continue.
Jabeur will face Linda Fruhvirtova in the next round of the competition.
Data Debrief: Top seed Jabeur through to next round
The world number 10 was at her clinical best, winning 84 per cent of her first serve points.
Jabeur's win saw her unbeaten record continue against Osorio, having last prevailed at Roland-Garros in May.
After rain delayed the match on Friday, and start of play on Saturday, a tough battle ensued, but Pliskova reached her third semi-final of the season with a 7-6 (10-8), 7-6 (7-3), 7-5 win.
Pliskova edged the first set on the tie-break before Jabeur forced a decider with an equally impressive win in the second.
Despite going toe-to-toe once more in the third, Pliskova just did enough to hold off top-seed Jabeur, getting a vital break to set up a meeting with Diane Parry.
Meanwhile, Emma Raducanu advanced to her first semi-final since 2022 after receiving a walkover from Francesca Jones, but her match against Katie Boulter was suspended due to rain after the first set, which lasted an incredible 80 minutes.
In 's-Hertogenbosch, Bianca Andreescu will play in the Libema Open final after her straight-sets 6-4, 6-2 victory over Dalma Galfi on Friday, earning a place in her first final of the season.
Data Debrief: Jabeur unable to stop the break
Jabeur had the opportunity to win seven break points during the quarter-final, but had a measly 14 per cent conversion rate (1/7). Pliskova, meanwhile, won half of hers (2/4).
The Czech also won 94 per cent of her service games (17/18), just one more than Jabeur. It was the fine margins that won out in Nottingham.
Gauff would have secured a career-high ranking on the WTA list if she had won Saturday's semi-final, but top seed Jabeur took it 7-6 (7-4) 6-2 to earn a shot at Belinda Bencic in the title match.
Only world number one Iga Swiatek has won more matches on the WTA Tour than fourth-ranked Jabeur this year, who collected a 29th win as she overcame a 3-1 career head-to-head deficit against Gauff to earn the victory.
Gauff, at 18 years and 98 days, would have become the youngest American to reach a grass-court singles final on tour since Andrea Jaeger was runner-up to Martina Navratilova at Wimbledon in 1983.
It was not to be her day though, Jabeur breaking serve for the fourth time in the match to seal victory, encouraged by a large and vocal Tunisian following.
Reflecting on the match, Jabeur said: "When you play Coco you have to have all the shots. She's a talented player; she's very tough to beat. You can see I've lost already three times against her.
"Sometimes she takes it, sometimes I take it, and it was a great match for both of us."
This is just the second WTA tournament where 27-year-old Jabeur has been a top seed.
"I've tried to act like a number one seed on and off the court, and it's a good pressure," she added. "I'm trying to handle it very well and with the support of our Tunisian people here it's great."
Olympic gold medallist Bencic had earlier claimed an impressive 6-7 (6-8) 6-4 6-4 win over Greek second seed Maria Sakkari in the first semi-final.
Jabeur was bettered by Bencic in a hard-fought Charleston final in April, but is determined to secure a different outcome this time.
"I'm definitely going for the final revenge because we played each other at Charleston, and it was a very, very tough match," Jabeur said. "I hope she's tired from today's match."
Rain meant there was no play at the Birmingham Classic on Saturday, with the semi-finals set back to Sunday.
Beatriz Haddad Maia will face 2019 Wimbledon champion Simona Halep, while Zhang Shuai tackles Sorana Cirstea.
Jabeur, who won her first and so far only WTA 1000 title in Madrid in 2022 then missed last year's tournament through injury, made it nine wins in a row in the Spanish capital to book a last-eight meeting with either Coco Gauff or Madison Keys.
Eighth seed Jabeur only needed 68 minutes to see off the former French Open champion, not dropping a game in a 21-minute opener in which she won 88 per cent of first-serve points.
Ostapenko improved in the second set, breaking back immediately after losing serve in the opening game, but Jabeur got the crucial break to go 5-4 up before serving the contest out.
Data Debrief: Jabeur dominates on the clay
Jabeur's win sealed her third quarter-final appearance at a WTA 1000-level event on clay since 2020. Only world number one Iga Swiatek (four) has reached more during that span.
A dominant start did the trick for the Tunisian on Monday, as she became the first player to take an opening set 6-0 against a top-10 ranked player in Madrid since the 2021 final, when Aryna Sabalenka did so in her victory over Ashleigh Barty.
Having lost to Aryna Sabalenka in her opening match in Fort Worth, US Open and Wimbledon runner-up Jabeur was staring down a group-stage exit from the tournament when she found herself 1-6 2-3 down halfway through the second set on Wednesday.
Yet the 28-year-old hit back to triumph 1-6 6-3 6-3 over her American opponent, the world number three, who has now lost both of her matches in the Nancy Richey group.
Jabeur reeled off four straight games to take the momentum and, after fending off four break points to hold serve in the first game of the deciding set, did not look back, clinching a decisive break to nose 5-3 ahead.
A stray Pegula cross-court forehand wrapped up Jabeur's comeback win, and the Tunisian, who is aiming to become the first African player to reach the semi-finals at the season-ending tournament, can now turn focus to her final group game against Maria Sakkari, who she has faced three times previously, losing twice.
Jabeur's victory was her third against a top-three opponent, after beating Simona Halep in 2018 and Karolina Pliskova in 2020, while only world number one Iga Swiatek has won more matches this season (47).
BREAK POINTS WON
Jabeur - 4/10
Pegula - 4/9
WINNERS/UNFORCED ERRORS
Jabeur - 27/29
Pegula - 11/16
ACES/DOUBLE FAULTS
Jabeur - 1/2
Pegula - 0/5
The Tunisian beat her American opponent 7-5 0-6 6-2, regrouping well after a major dip in the second set to scoop the biggest title of her career.
The history-making victory means Jabeur will jump from 10th to seventh in the WTA rankings on Monday, matching a career high, and she earns €1,041,570 in prize money.
After losing to Belinda Bencic in the Charleston Open final last month, Jabeur's run on the Spanish clay shows she is becoming increasingly resilient, and comes as a timely boost ahead of the French Open getting under way in two weeks' time.
"We've lost a lot of finals, but today I'm happy I pulled out the win," Jabeur said at the end of the match, addressing her support team.
"It was very tough, especially last time in Charleston, so thank you guys for always believing in me and pushing me forward."
Jabeur came from 4-1 behind to take the opener, and she now holds a 17-0 match record when winning first sets this year.
Pegula broke in the fourth game, having fended off three break points in the opening game of the contest. Jabeur hit back and soon had the match back on serve, before saving a set point with a thumping backhand.
The 28-year-old Pegula, daughter of Buffalo Bills owners Terry and Kim Pegula, has carved out a successful career at the top level in tennis, reaching back-to-back Australian Open quarter-finals this season and last.
She was in trouble when she lost her serve in the 11th game though, and Jabeur capitalised to snatch the opener.
Pegula made a flying start to the second set, establishing a swift double break, and a flat Jabeur found no way back. A drop shot into the net on set point summed up her drastic drop in level.
Jabeur stopped the rot by breaking serve at the start of the decider. Pegula immediately got back on level terms, but another break for Jabeur saw her pull away, on her way to victory in an hour and 54 minutes, a tour-leading 12th win of the season on clay.
The impressive Jabeur is also the first Arab winner of a tournament at this lofty level.
Williams has not played a competitive match since defeat to Aliaksandra Sasnovich in the first round of last year's Wimbledon and is now ranked at 1,204 in the world.
The 40-year-old, who is one grand slam title shy of matching Margaret Court's long-standing record of 24, will feature at the third grand slam of the year, which starts next Monday.
Eastbourne will serve as preparation for the upcoming grass-court major after Williams received a wild card in the doubles draw alongside Jabeur.
Jabeur has been in fine form in 2022, winning the Berlin Open and Madrid Open and rising to world number three, though she remains nervous to play with Williams at Eastbourne.
"I wanted to tell everyone, but obviously I couldn't," Jabeur told the WTA Tour in an interview. "I told my family, but even my close friends, I didn't tell anyone.
"Excited, really lucky that she picked me. I'm pretty glad that I can share the court with her. I always watched Serena playing and always supported her.
"She's such a legend and such an example for our sport. I'm really nervous to play. I hope the match will be great and we'll have great matches.
"I don't know why she picked me to be honest. Maybe she watched Madrid. I met her a few times outside the court and she was always nice.
"I remember exchanging pins with her in Rio. I respect her so much. I've been waiting for this moment for a long time. I had to take my time in Berlin, but now it's Eastbourne. I cannot wait for this moment."
Williams and Jabeur have been drawn against unseeded duo Marie Bouzkova and Sara Sorribes Tormo in the first round on Tuesday.
Gauff joins other big names in exiting the WTA 1000 event, with Naomi Osaka, Garbine Muguruza, Danielle Collins, Paula Badosa and Maria Sakkari among those crashing out in the second round.
The number 14 seed did not put up much resistance against her Romanian opponent, with Halep winning 6-4 6-4 in just 77 minutes.
Gauff struggled on her own serve in particular, making six double faults and only winning 61.5 per cent of her first-serve points, compared to 83.8 from Halep on hers.
The former world number one and two-time Madrid champion will now face the only remaining top-eight seed in the tournament in the quarter-final, Jabeur, who defeated Bencic 6-2 3-6 6-2.
The Tunisian was out for revenge after losing to Bencic at the same stage last year, as well as in the Charleston Open final last month, and took it well as she sealed victory in just over two hours.
"I came here to take my revenge," Jabeur said after the win. "I wish I played like that in the final in Charleston, to be honest.
"Part of me is very proud of myself for coming today and getting the win. Belinda is such an amazing player and it's very tough to play against her. I'm very happy with the level I showed today, and hopefully this level will continue for the rest of the tournament."
Elsewhere, Victoria Azarenka is out after the number 15 seed was beaten 6-1 6-4 by Amanda Anisimova, who will now face Ekaterina Alexandrova in the last eight after she overcame Marie Bouzkova 6-7 (4-7) 6-0 7-5.
