Maria Sharapova has claimed that she had to step up her game for the first round of the US Open due to the threat posed by fellow Russian Maria Kirilenko.
The former world number one was well matched in the first set but sailed through the second as she secured a 6-4 6-0 victory at Flushing Meadows.
"It's always tough," the 27-year-old told reporter after the match. "I played a tough opponent who is capable of playing really good tennis so it was a tough first round for me.
"I'm happy I stepped it up and I was able to finish really strong."
Meanwhile, Andy Murray survived a first-round scare to grab victory over Robin Haase in four sets.