Sam Stosur takes on Flavia Pennetta in the first of Friday's quarter-finals at the Mercury Insurance Open.

You can watch Stosur v Pennetta live for free at bet365>live streaming>tennis

Second seed Stosur received a first round bye before making a solid start to her San Diego campaign, serving her way to 6-4, 6-4 win over American teenager Melanie Oudin. Stosur quickly fell 3-1 down but once her game clicked into gear there was only ever going to be one winner, Stosur powering down a succession of brutal topspin serves which Oudin struggled to handle.

Fifth seed Pennetta has eased into the last eight without dropping a set. She beat close friend Maria Kirilenko 6-4, 7-6, overcoming a second set wobble which saw her slip 5-2 down.

"After the first set I relaxed a bit and she started playing better and more aggressively,” Pennetta said. “I was too far from the baseline and not aggressive enough, but I started to play my tennis again."   

Pennetta enjoys a very good record against Stosur and has beaten her twice on hard courts, winning 6-4, 6-3 in last year's Los Angeles final and 6-3, 6-1 in Sydney at the start of 2010.

Looking ahead to the match the Italian intimated it would all depend on how she deals with the Stosur serve. "I have to be ready to run a lot,” she said, “She's really powerful - my return will be key."   

You can watch Stosur v Pennetta live for free at bet365. To watch, simply follow these 3 simple steps:

1. Go to bet365 and sign-up or register (it's free)
2. Click on Sports > Live Streaming > Tennis
3. Watch WTA San Diego for free