Coco Gauff survived a match that lasted nearly three hours on Wednesday to upset second-seeded Aryna Sabalenka of Belarus 7-6 (4), 4-6, 6-4 and advance to the quarterfinals at The Top Seed Open in Lexington, Ky.

Both players struggled with their serves in the first tournament in the U.S. since the hiatus caused by the coronavirus pandemic, with a combined 19 double faults (11 by Sabalenka) and 14 breaks of service (seven each).

Gauff rallied from a break down in the first set, then blew a 5-3 lead by being broken in back-to-back service games. But Gauff broke right back to force a tiebreaker, where she stormed out to a 5-0 lead before wrapping it up.

Gauff hung on temporarily late in the second set but then dropped it on her own serve. In the third, Sabalenka rallied from a break down to even it twice, but Gauff broke again at 4-4 and served out to win in 2 hours, 48 minutes.

Sixth-seeded Magda Linette of Poland also fell to an American, as Jennifer Brady cruised to a 6-2, 6-3 victory in just 68 minutes.

In other matches Wednesday, No. 8 Ons Jabeur of Tunisia overcame a rough start to beat Olga Govortsova of Belarus 3-6, 6-2, 6-4, and the Czech Republic's Marie Bouzkova downed Russia's Anna Blinkova 6-4, 6-2.

Prague Open

Kristyna Pliskova of the Czech Republic upset second-seeded Petra Martic of Croatia 6-1, 7-5 to advance to the quarterfinals.

Pliskova, ranked 69th, had nice aces and just one double fault in downing her 14th-ranked opponent. Pliskova will face Ana Bogdan of Romania in the next round. Bogdan advanced when Ukraine's Lesia Tsurenko withdrew due to a rib injury.

In Wednesday's other singles match, third-seed Elise Mertens of Belgium beat Camila Giorgi of Italy 6-4, 6-2. Mertens will play either Slovenia's Tamara Zidansek or Canada's Eugenie Bouchard in the quarterfinals.