In this Jan 26, 2020 photo, Coco Gauff of the US hits a return against Sofia Kenin of the US during their women's singles match on day seven of the Australian Open tennis tournament in Melbourne. (JOHN DONEGAN / AFP)

WASHINGTON - US teenager Coco Gauff beat second seed Aryna Sabalenka of Belarus 7-6 (4), 4-6, 6-4 on Wednesday to reach the quarterfinals of the WTA Top Seed Open in Lexington, Kentucky.

Aryna Sabalenka had 14 double-faults, including four in one game, as Coco Gauff notched her second Top 20 win of the season over the Belarusian

16-year-old Gauff won in two hours and 48 minutes, despite hitting 10 double-faults and having her serve broken seven times.

"I think my mentality pushed me to win," Gauff said after the match. "We're both playing good tennis, and had our ups and downs in the match. At the end of the day, it came down to a couple of close points."

Sabalenka had 14 double-faults, including four in one game, as Gauff notched her second Top 20 win of the season over the Belarusian.

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The American will face No 8 seed Ons Jabeur on Friday, after the Tunisian eliminated Sabalenka's compatriot Olga Govortsova 3-6, 6-2, 6-4 on Wednesday.

In another second round match, Marie Bouzkova of the Czech Republic beat Russia's Anna Blinkova 6-4, 6-2.

Local player Jennifer Brady toppled sixth-seeded Magda Linette of Poland 6-2, 6-3 in Wednesday's final match.

Thursday's second round action will also include the 31st career matchup between Serena Williams and her older sister, Venus.