PETRA KVITOVA and Serena Williams began their Wimbledon title bids today knowing that Maria Sharapova has already sent out an ominous warning sign.
Russian Sharapova comprehensively saw off Anastasia Rodionova yesterday, flirting with brilliance as she dropped just three points in racing into a 5-0 lead, before the brakes were applied and she settled for a 6-2 6-3 win.
It is only just over a fortnight since the 25-year-old won the French Open, but last year's Wimbledon runner-up believes her performance showed she has no intentions of letting up.
"The first one is always tricky," she said. "I thought I started off the match really well. "It was a nice feeling to be back on Centre Court. It's such a special place for me.
"I'm still very humble and appreciative for what I have. I still believe I can achieve a lot more. That's what drives me and gets me up in the morning."
Meanwhile, questions have been raised about the future of Venus Williams's tennis career. Williams, the 32-year-old five-time winner, was subjected to just the second first-round exit of her illustrious Wimbledon career when she lost 6-1 6-3 to Elena Vesnina.
Ill health has plagued her over the last two years, after being diagnosed with the autoimmune, fatigue-inducing illness Sjogren's syndrome, and she was asked if she was struggling - a question which received an animated response.
"Am I struggling?" Williams said. "Am I? I don't know. Tell me what the struggle is. I just want you to be clear. If you say I'm struggling, tell me how I should do better. I feel like I am a great player.
"I am a great player. Unfortunately, I had to deal with circumstances that people don't normally have to deal with in this sport."
It was the former world number one's earliest loss at Wimbledon since she went out in the first round on her debut here in 1997, and followed her second-round defeat at Roland Garros last month.
Other impressive winners yesterday included Kim Clijsters against Jelena Jankovic (6-2 6-4) and Britain's Heather Watson, who rarely looked the lower-ranked player in seeing off Czech Iveta Besnova 6-1 6-2.
The ever-popular former world number one Caroline Wozniacki was set to kick off her bid today against Austrian Tamira Paszek on Court Two.