NEW YORK - China's Zheng Qinwen shook off slow starts in the opening two rounds of the US Open and took down unseeded German Jule Niemeier 6-2 6-1 at the US Open on Friday.

The Olympic gold medalist and 7th seed fired off eight aces and seized five break points on the Grandstand hard court in her first straight-sets victory of the year's final major.

Niemeier, nursing a foot injury, committed five double faults and held serve in just three games of the match that wrapped up quickly in an hour and 21 minutes.

Zheng was sharp from the start, blasting two aces to open the second game and breaking Niemeier's serve in the fifth to seize control of the match and energize scores of Chinese chanting "jiayou" from the stands.

A cross-court forehand blast captured a second service break for the 2024 Australian Open runner-up as Niemeier's forehand return found the net.

ALSO READ: Comeback Queen Wen battles on

Zheng grabbed seven straight points to open the second set and cruised to the win, avenging a third-round loss to the German at her first US Open in 2022 and setting up a fourth-round clash with Croatian Donna Vekic, whom she beat in the Olympic final earlier this month.

"Finally, it's the first match I won in two sets ... It's not (been) easy for me to play after Olympic Games," said Zheng, who has noted previous struggles with focus after deep tournament runs.

Vekic, who beat American Peyton Stearns 7-5 6-4, said she was optimistic that she would do better against Zheng on New York's hardcourts just a few weeks after coming off second best on clay at the Paris Games.

"She played an unbelievable match in Paris. She was too good that match. I had couple of chances but didn't manage to pull them off," the 24th seed told reporters.

READ MORE: US Open: Three Chinese players into third round

"But it's a new match. We're a couple of weeks later. It's a different surface, thankfully for me."