Coco Gauff's defence of her WTA Finals title got off to a losing start as she was beaten in three sets by Jessica Pegula in Riyadh on Sunday. 

Gauff, who downed Zheng Qinwen in last year's final, failed to find her groove against her compatriot as Pegula recorded a brilliant 6-3 6-7 (4-7) 6-2 triumph. 

Both players struggled on serve in the opening exchanges, with five consecutive breaks eventually ending in the sixth game by Pegula, who claimed the early lead.

Pegula needed three attempts to take the first set, but Gauff dusted herself down and started the second with a break of her own as she looked to find an immediate response. 

However, Pegula got the better of Gauff's serve in the 10th game, before the pair traded breaks again, but the defending champion edged the tie-break to see the match go the distance. 

The theme of the encounter continued as both players conceded early breaks, but Gauff's momentum eventually faded as Pegula took control in the closing stages. 

Pegula reeled off the final five games in comfortable fashion, sealing her winning start to the tournament after Gauff returned a serve long of the far baseline. 

Hey Jessie! @JPegula fights her way through another three set match to defeat Gauff 6-3, 6-7(4), 6-2. #WTAFinalsRiyadh pic.twitter.com/k0vKz2Mt4a

— wta (@WTA) November 2, 2025

Data Debrief: Pegula proves age is just a number

While both players were far from their very best, Pegula used her experience to put Gauff to the sword on Sunday. 

Indeed, Pegula is the first player to defeat the WTA Finals' defending champion at the round-robin stage since Karolina Pliskova in 2018 against Caroline Wozniacki.

She is also the second player in 2025 to win against all the current top three of the WTA Rankings (Iga Swiatek in Bad Homburg, Aryna Sabalenka in Wuhan and Gauff at the WTA Finals) after Amanda Anisimova.