Serena Williams has continued her hard-court comeback, and has set up a quarter-final showdown with fellow former world No. 1 Maria Sharapova, after defeating Maria Kirilenko 6-2 3-6 6-2 at the Bank of the West Classic in California.

27288 - Williams sets up Sharapova showdown

Williams fired down 14 aces en route to victory, as she overpowered the Russian to book her place in the final eight of the tournament.

After losing the second set, the American showed the fight which took her to the top of the women's game, breaking Kirilenko in two consecutive service games in the deciding set to set up an enticing showdown with Sharapova.

Meanwhile, tournament top seed Victoria Azarenka suffered a shock defeat at the hands of New Zealand qualifier Marina Erakovic 4-6 7-5 6-2. The 121-ranked Erakovic reached her second quarter-final of the season, and notched her first win over a top-20 opponent, as she humbled this year's Wimbledon semi-finalist in three sets.

Fellow qualifier Urszula Radwanska of Poland was not so fortunate against Ayumi Morita, as the Japanese dynamo powered to a 4-6 7-5 6-1 victory, while Sabine Lasicki battled to a 6-3 7-5 win over Australian Sam Stosur in the final match of the day.