Coco Gauff captured the biggest title of her career on Sunday, powering past Karolina Muchova 6-3, 6-4 to win the WTA Cincinnati Open.

The 19-year-old American rushed to her box to hug her team members after securing victory at the 1000-level event over French Open runner-up Muchova in just under two hours.

Gauff was broken while serving for the straight-sets win, but two games later threw her hands up in joy after converting on her fourth match point.

"This is unbelievable," said Gauff, who became the first teenager to win five career titles since Caroline Wozniacki in 2008-09.

"Especially after Europe," added the seventh seed, who was stung by a first-round exit at Wimbledon last month. "I had a lot of nights crying and trying to figure it all out but this is great."

Gauff fired 16 winners with the same number of unforced errors in the final, breaking Muchova five times.

Since losing in the opening round at Wimbledon, Gauff has won 11 of her last 12 matches with her only defeat coming against Jessica Pegula last week in the Montreal quarterfinals.

Despite that hiccup she'll go into the US Open starting in eight days on a high.

She has now won five of her six career finals, including her first 500-level event at Washington two weeks ago and her first 1000-level title in Cincy, where she beat world No 1 Iga Swiatek in the semifinals.

Muchova will turn 27 on Monday with a career-best ranking of 10th.

"When I woke this morning I knew I would have a tough task today," she said. "It would be difficult to win, especially against Coco here.

"She's had an incredible run this week, she has a very strong game."

Gauff and Muchova twice exchanged breaks in the opening set, with the American coughing up three double-faults to lose the third game and dropping serve again in the seventh.

But a final break of the Czech off a backhand error handed the set to the crowd favourite after 44 minutes.

Gauff went up two breaks in the second set, giving back one before she closed out the victory.