Victoria Azarenka is determined to remain patient in her search for improved form after battling into round two of the WTA Silicon Valley Classic.
A two-time Australian Open champion and former world number one, Azarenka has endured a prolonged spell away from the court due to a protracted custody battle.
On Monday, in her first outing since Wimbledon, she overcame fellow mother Kateryna Bondarenko in a gruelling three-setter, eventually prevailing 6-3 6-7 (7-9) 7-5 in two hours and 40 minutes.
In an on-court interview following her win, the 29-year-old said: "It's a really challenging time for me and my game right now. You can see with my game, there's a lot of ups and downs. The important thing is that I'm here, I'm fighting hard, and I try to do my best. That's all I can ask of myself, but it's not easy.
"Everyone expects to have results right away - I do too - but I need to be patient, and keep working hard."
Azarenka will be an underdog in her second-round tie against top seed Garbine Muguruza.
Monday's final match saw American teenager Ashley Kratzer survive a late wobble to overcome Alison Riske. Kratzer triumphed 7-5 in the third having led 5-1 only to be pegged back to 5-5.
There were wins in straight sets for Maria Sakkari, Sofia Kenin, Ajla Tomljanovic and Danielle Collins, while Serena Williams is among those in action on Tuesday.