Heather Watson wins in Carlsbad but Anne Keothavong is out
Heather Watson marked her first week as British number one with victory over Eleni Daniilidou in round one of the Mercury Insurance Open in Carlsbad.
The 20-year-old, who won the Bank of the West Classic doubles title on Sunday, beat 112nd-ranked Daniilidou of Greece 6-3 6-3 at the California event.
Watson next meets seventh seed Yanina Wickmayer or qualifier Chan Yung-Jan.
But British number two Anne Keothavong is out after she succumbed 6-4 6-0 to Marina Erakovic of New Zealand.
Keothavong also lost in the doubles, going down 6-2 1-6 10-8 against Kai-Chen Chang and Noppawan Lertcheewakarn.
But Watson progressed as she and Slovak team-mate Janette Husarova overcame fourth seeds Natalie Grandin and Vladimira Uhlirova 6-4 7-5.
At the Swedish Open in Bastad, Laura Robson lost 6-4 7-6 (7-4) to third seed Anabel Medina Garrigues in the opening round.
Robson reached her maiden WTA semi-final at last week's Italiacom Open and plays doubles with Watson at the Olympics.
Keothavong and Elena Baltacha will represent Team GB in the singles