LONDON (Reuters) - Twice former champion Serena Williams took one step closer on Tuesday to another Wimbledon final against her sister Venus, winning through to the last four with an easy 6-4 6-0 victory over Poland's Agnieszka Radwanska.

Serena, who defeated Agnieszka's younger sister Urszula in the second round, dashed the Polish family's Wimbledon hopes again on Centre Court with a perfectly honed power game.

The sixth seed, who like Venus has concentrated her year on peaking for Wimbledon, dropped service once in the first set but constantly unsettled the 19-year-old and never let her find her rhythm.

Serena, who has yet to drop a set at Wimbledon this year, joined Venus in the semi-finals by clinching the second set with consummate ease. She utterly dominated the match from the baseline and served 11 aces.