Amanda Anisimova came from a set down to clinch victory in a winner-take-all clash against Iga Swiatek at the WTA Finals.

The victor of Wednesday's encounter would receive passage to the semi-finals as their reward.

And Swiatek, who beat Anisimova 6-0 6-0 in the Wimbledon final earlier this year, seemed to have the edge when she took the opening set tie-break.

But two-time grand slam finalist Anisimova roared back to prevail 6-7 (3-7) 6-4 6-2.

It marks Anisimova's second three-set win of this year's tournament, and she will now play the winner of the Steffi Graf Group, which will be decided on Thursday.

The American claimed the decisive break in set two right at the end, after the second deuce.

She swung the decider in her favour earlier on, and capped off a fine comeback with her second break of the set, sealing victory with a crisp forehand return.

2 - Including all levels, Iga Swiatek has lost two matches in a row after having won the opening set for the first time in her career. Braking.#WTAFinalsRiyadh | @WTA @WTAFinalsRiyadh pic.twitter.com/Iv9ur7ff1j

— OptaAce (@OptaAce) November 5, 2025

Data Debrief: Swiatek slips up again

Swiatek has lost two matches in a row after having won the opening set for the first time in her career.

Anisimova, meanwhile, is the third American to reach the semi-final in her first appearance at the WTA Finals since 2000, after Serena Williams (2001) and Sloane Stephens (2018).

Indeed, two Americans (Anisimova and Coco Gauff) have claimed 10+ WTA top-10 wins in the same season for the first time since 2002, when the Williams sisters did so.