London-bound Christina McHale has defeated Australian Jarmila Gajdosova at the WTA hardcourt event in Carlsbad, in a first round that featured mixed results for Olympic hopefuls.
The American fifth seed battled past Gajdosova 7-6 (7-5) 7-5 at the California event, which offers a final chance to warm up for the Games tennis competition at Wimbledon.
McHale, the world No.27 who reached the Wimbledon third round, recovered from a break down against Gajdosova to take the opening set with a backhand winner down the line.
The American took the second thanks to a break of serve in the penultimate game, winning after almost two hours with nine aces.
McHale is due to join Venus and Serena Williams and Varvara Lepchenko on the US Olympic team.
New Zealand's Marina Erakovic, also headed to the Olympics, beat British Olympic hope Anne Keothavong 6-4 6-0 in just over an hour and a quarter with five breaks of the Brit's serve.
"It was a tricky first round. Anne comes out hitting some big balls," said the Kiwi ranked 47th.
"She doesn't give you much rhythm, but just getting into the match and settling down helped. I'm just getting used to the surface and moving well and trying to keep relaxed and positive as I can."
Seventh seed Yanina Wickmayer, a semi-finalist last week up the coast at Stanford and also London-bound, had to retire against trailing qualifier Chan Yung-Jan of Taiwan 7-6 (8-6) due to a back injury.
Chan next faces Britain's Heather Watson, who beat Eleni Daniilidou of Greece 6-3 6-3.
American Vania King, a 6-1 6-4 winner over Taiwan's Chang Kai-Chen, will be the first opponent for top seed Marion Bartoli of France, who received a first-round bye along with second seed Dominika Cibulkova, third seed Jelena Jankovic and fourth seed Nadia Petrova.