Happening Now(WATCH): As Iga Swiatek expressed her gratitude to fans and the WTA after it emerged that Coco Gauff couldn’t save her…

Gauff earned the straight-sets victory needed to guarantee her spot in the final four in Riyadh, knocking out the former world No. 1 for only the second time in 13 meetings.

Coco Gauff pulled off a massive upset at the 2024 WTA Finals, defying a 1-11 head-to-head against Iga Swiatek to stun the former world No. 1, 6-3, 6-4 and guarantee herself a spot in the semifinals.

The No. 3 seed not only needed to snap a four-match losing streak against Swiatek to advance out of round-robin play regardless of subsequent results from the Orange Group, but she also needed to win in straight sets. Gauff managed both to close out play on Day 4, conquering Swiatek in one hour and 48 minutes on Riyadh’s Center Court.

Whether Gauff advances first or second out of the Orange Group is to be determined by the final rotation of matches on Thursday. Jessica Pegula has been eliminated from contention, leaving the second spot to be filled by either Swiatek or Barbora Krejcikova, who defeated Pegula in straight sets earlier in the day.

Swiatek’s loss also guarantees Aryna Sabalenka will end the 2024 season as world No. 1.

Gauff has endured an up-and-down follow-up to her breakout 2023 season, one that culminated with her first Grand Slam title at the US Open. Though she began the year with back-to-back major semifinals at the Australian Open and Roland Garros, serve and forehand woes followed her through the summer and saw her Flushing Meadows title defense end behind a flurry of double faults.

The 20-year-old rebounded somewhat in Asia, winning the China Open but suffering another tragic serving day at the Dongfeng Voyah Wuhan Open, where she narrowly lost in in the semifinals to Aryna Sabalenka.

In Riyadh with new coach Matt Daly, Gauff opened with a strong performance against fellow American Jessica Pegula to book a meeting with Swiatek, who roared back from a set and two breaks down to defeat Barbora Krejcikova.

Facing the Pole on hard courts for the first time since last year’s WTA Finals, Gauff pressured Swiatek early, forcing her to save three break points in her second service game. Though Swiatek, who is also at the WTA Finals with a new coach—having hired Wim Fissette after a US Open quarterfinal exit to Pegula—dug out of the long game, she found herself on the back foot again and again, ultimately giving up two breaks to hand Gauff the opening set.

The second set got closer as some of Gauff’s service issues reared back up—nine double faults to only two in the first set—and Swiatek twice led by a break. Gauff quickly reclaimed the initiative both times and put down a strong service hold to put herself on the brink of a very big win.

Swiatek was dealing with visible frustration on top of a relentless onslaught from Gauff, who outrallied the Pole to earn a match point. A bold final gambit by Swiatek failed to pay off as a forehand swing volley flew long, putting Gauff over the finish line in just under two hours.

Gauff will end her round-robin campaign against Krejcikova, while Swiatek will face Pegula for the first time since losing their match at the US Open