Washington - Yanina Wickmayer beat Lauren Davis 6-4, 6-2 in the Citi Open final on Sunday to win the fifth WTA title of her career.
Wickmayer, a 26-year-old Belgian who was seeded No 7 at the hard-court tournament, is the third woman to win both the singles and doubles championships at the same event this season.
She teamed with Monica Niculescu to win the doubles at the Citi Open on Saturday.
"It's such a great feeling to win titles and to hold that trophy at the end of the week," said Wickmayer, who entered with a ranking of 44th.
"Being able to hold two trophies this week has been great."
In her only other appearance in Washington, in 2013, Wickmayer lost in the first round.
This was the first singles title of the season for Wickmayer, whose best Grand Slam showing was a run to the semi-finals of the US Open in 2009.
She said playing in both singles and doubles while dealing with the heat that was in the 90s for much of the tournament was not easy.
"It was a real battle out there every day, mentally and physically," Wickmayer said. "I just had to stay strong every day. I was feeling tired by the end of the week."
Davis is a 22-year-old American who is ranked 122nd and was playing in her first WTA final.
She had won only three main-draw, tour-level matches all year until winning four in a row on the way to reaching the title match at the Citi Open.
"I know how it felt being out there the first time in my career, playing a final," Wickmayer said. "It's not easy."