THIRD seed Serena Williams advanced to the U.S. Open quarterfinals after a gritty, tension-filled 6-3, 6-7(6), 6-3 win over Greece’s Maria Sakkari.

Serena came into Monday’s contest with something to prove. After losing to Sakkari at the Western & Southern Open in August, Williams was hungry for a win.

Williams won the first set 6-3, but lost a tie break to Sakkari in the second set. With the match on the line, Williams rose to the occasion, beating Sakkari 6-3 in the third set.

With the win, Williams, 38, advanced to the quarterfinals. She’ll take on Tsvetana Pironkova in the next round.

While Williams advanced, another American saw her dreams of her first U.S. Open title dashed.

No. 16 seed Elise Mertens of Belgium delivered a dominant 6-3, 6-3 win Monday night to send No. 2 seed Sofia Kenin home early.

The 21-year old Kenin won the Australian Open in February and had her eyes on her second Grand Slam title as one of the favorites at the U.S. Open. She will instead set her sights on the French Open, which starts Sept. 27 after its usual spring schedule was delayed due to the COVID-19 pandemic.

“I cried after already,” Kenin told reporters as she confirmed her Roland Garros plans. “Just trying to hold it back right now. Not happy about that match.”

Bertens advanced to the quarterfinals, where she’ll face unseeded Victoria Azarenka of Belarus.

With Sunday’s unceremonious exit by Novak Djokovic, the door to a first Grand Slam victory blew wide open for Dominic Thiem. The No. 2 seed at the U.S. Open looked like the new favorite Monday in a straight-set win over No. 15 seed Felix Auger-Aliassime.

The Austrian needed a tie break to secure the first set. But he was dominant the rest of the match, cruising to a 7-6 (7-4), 6-1, 6-1 win to advance to the quarterfinals.

Thiem has never reached the U.S. Open semifinals. He’ll face No. 21 seed Alex de Minaur next with a chance to do so. Thiem has made the French Open final twice and advanced to the Australian Open final in February, where he lost to Djokovic in five sets.(SD-Agencies)