BEIJING, China (AFP) — Coco Gauff overpowered Karolina Muchova in straight sets to win the China Open on Sunday for her second title of the year and eighth overall.

The 20-year-old American and last year’s US Open champion stormed to victory 6-1, 6-3 in one hour, 16 minutes in Beijing.

After a disappointing few months by her standards, including surrendering her New York crown in the last 16, Gauff added the China Open to her triumph in Auckland in January.

The sixth-ranked Gauff was under a new coaching team in the Chinese capital after splitting with Brad Gilbert last month.

“Today was by far my best match in a while,” said Gauff, whose mother was court-side to see her biggest win since the US Open.

She said keeping relaxed was key.

“I think I’m realizing more and more each day that tennis is not a measure of my value as a person,” she said.

“I think the more you realize that, the more relaxed these tournaments become.”

It was Gauff’s third straight-sets win in as many matches against Muchova, who suffered a career-threatening wrist injury and missed 10 months of tennis before returning this summer.

It proved one match too far for Muchova, who at 49 in the world was the lowest-ranked finalist in the history of the prestigious WTA 1000 tournament.

“You kicked my butt,” the Czech player, last year’s French Open finalist and a two-time US Open semifinalist, told Gauff.

Muchova — who beat top seed Aryna Sabalenka in the Last Eight -- called it her “weakest performance” of the tournament.

“Coco outplayed me today and I helped her a little bit.”

“She pushed me and made me do those errors, but I did not help myself with my serve, which is my game usually.”

Gauff made a fast start, breaking for a 2-0 lead and then holding her own serve without conceding a point.

The young American was up 3-0 with barely 10 minutes on the clock.

The 28-year-old Muchova sent down an ace to get on the board but Gauff was in the mood and her serve -- her biggest problem of late — was firing.

Gauff had three break points in the sixth game and converted the first to streak to a 5-1 lead against a shell-shocked Muchova.

Gauff rattled off her third ace of the match to give her two set points.

Her serving wobbles momentarily returned but she wrapped the first set up in 29 minutes on her third set point.