Wins for Watson and Robson
Heather Watson made a winning return to the court with a 6-7(5) 6-4 6-3 first round victory over qualifier Alexandra Mueller at the Citi Open in Washington - while Laura Robson fought back to progress in California.
On Monday, British No. 2 Watson revealed she was targeting a more aggressive approach to her game following her recent split from coach Mauricio Hadad, but she was made to work hard by American Mueller.
Watson had to come from a set down to take victory at the FitzGerald Tennis Centre as Mueller clinched the first on a tie-break.
However, the 21-year-old battled back in the second to send the match into a decider. Despite gaining an early break in the third, Watson was immediately broken back as world No. 499 Mueller refused to back down.
Watson regained the advantage in the seventh game of the final set, before confirming the break with ace number 14 to hold her serve and move firmly into the lead.
After two hours and 10 minutes on Court Two, Watson's victory was complete when Mueller failed to defend her serve for a final time.
The Brit will play fourth seed Alize Cornet after the Frenchwoman saw off Yanina Wickmayer in straight sets.
Elsewhere, top seed Angelique Kerber defeated home qualifier Irina Falconi 6-2 6-3, Mona Barthel enjoyed a 6-2 6-2 win over Stefanie Voegele and Monica Niculescu only dropped three games in her 6-3 6-0 win against Taylor Townsend.
Meanwhile at the Southern California Open, British No. 1 Robson came from a set down to overcome Ayumi Morita 4-6 7-5 6-2, and she will now face former Wimbledon champion Petra Kvitova in the next round.