Heather Watson was celebrating the first WTA title of her career after she and partner Marina Erakovic won the Bank of the West Classic.
Watson and Erakovic, playing together for the first time, beat top seeds Vania King and Jarmila Gajdosova 7-5 7-6 (9/7) in the final in Stanford.
The 20-year-old Briton and her New Zealand team-mate had already beaten the second and third seeds on their way to the final.
After breaking three times to win the opening set, Watson and Erakovic fell a break down at the start of the second.
They battled back to serve for the match at 5-3 but were broken, then threw away two match points on their opponents' serve, but held firm to take the second set on a tie-break.
For Watson, who reached the second round in the singles draw, it was the perfect warm-up for the Olympics, where she will represent Great Britain in the doubles, partnering Laura Robson.
She will play in the Mercury Insurance Open in California next week before heading back to Britain for the start of London 2012.
Watson said: "This is my first WTA title so I'm really happy right now.
"It's such a nice feeling getting to the end of the week and being the last ones here.
"We knew it wasn't going to be an easy match today - they're both great players and we knew we would really have to win it, they weren't going to give it to us."
While there was success for Watson in the US, compatriots Colin Fleming and Ross Hutchins were beaten in their doubles final on Sunday.
Up against Santiago Gonzalez and Scott Lipsky in Newport, Rhode Island, the British duo went down 7-6 (7/3) 6-3 as they missed out on their third title of the season.
