Serena Williams produced some of her best tennis on her way to a convincing straight-sets victory over Maria Sharapova in the Madrid Open quarter-finals.

The 13-time Grand Slam champion was in complete control during the first set, dropping just one game and breaking the Russian twice as she won the opener 6-1.

Another break in the first game of the second set gave her more momentum, but on this occasion, Sharapova was able to respond by winning consecutive games to level the scores at 2-2.

Williams restored her lead by winning two straight games of her own and then showed great determination to hold after Sharapova had forced her to deuce.

A final break of serve secured the match for the American, who continued her fine head-to-head record against the 25-year-old.

Williams could face her US Open final conqueror Samantha Stosur in the last four, providing the Australian beats qualifier Lucie Hradecká.