Maria Kirilenko and her boyfriend Igor Andreev wanted to start 2010 with a bang.
"Before the matches he said that we can start the year loud (with a big upset)," she said.
"And I have already started the year loud, I think. So now it's his turn. Of course, it's going to be tough, but in the first round you never know what's gonna happen."
Kirilenko had beaten her good friend Sharapova once before, at Beijing in 2005, but Monday's unexpected win was all the sweeter because it was at a Grand Slam.
The pair won a doubles title together at Birmingham in 2005 when they were teenagers but while Sharapova's career has gone from strength to strength, Kirilenko's has stalled.
She has won five WTA Tour titles but her best result at a Grand Slam was reaching the fourth round at Melbourne Park in 2008.
Kirilenko reached a career high ranking of 18 that year but has slipped to 58 after experiencing knee problems in 2009.
"I had a knee problem last year, actually here in Australia," she said. "I was not so good and after Wimbledon, I started to get some treatment.
"Since then, I've had a lot less pain. For example, today I played three-and-a-half hours and I didn't have any pain. And I was moving quite good, I think."
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