By Sarah Holt
BBC Sport at Wimbledon
Venus Williams prevailed in the battle of the former champions, defeating 2004 winner Maria Sharapova 6-1 6-3.
Venus won the Wimbledon title in 2000, 2001 and 2005
The three-time winner took advantage of the second seed's error-strewn play to wrap up the first set in 33 minutes.
With the second set tied at 1-1 rain delayed play for almost two hours, but when the match resumed there was no let up for Sharapova as Williams attacked.
The American got the inevitable break at 4-3 and broke again to set up a quarter-final with Svetlana Kuznetsova.
"I played solid and my serve was definitely a weapon, though my returns were also good," said Williams, who has been seeded 28th for the tournament.
"I've always been a big match player and it was probably a tougher draw for Sharapova than it was for me.
I'm not going to let my head hang - I look forward to better days
"I know I have a huge game that some players don't have and I always believe in myself 100%."
An erratic fourth game saw the opening set slide away from Sharapova, who slung down four double-faults to hand Williams the break and a 3-1 lead.
While the Russian struggled with her serve, the American was in fiercesome form, getting 74% of her first serves in and following them up with booming forehands.
With the second set poised at 1-1 and Sharapova on advantage in her service game, the skies opened without warning.
The players, who only got through three points on Tuesday before rain postponed their match, ran for refuge and emerged to resume their encounter almost two hours later.
Sharapova made 21 unforced errors on her way to defeat
An immense game followed, with Sharapova saving seven break points and battling through 14 deuces to hold on to her serve.
While Williams sailed through her service games, Sharapova was forced to fend off break points in each game, and it was only a matter of time before she succumbed again, looping a forehand long to fall 4-3 down.
There was no way back then for the Russian, who was broken again to see Williams complete a whitewash in one hour, 29 minutes on Centre Court.
Sharapova said Williams' serve had been too strong as she went out in straight sets to the American in the fourth round.
"At the end of the day her first serve was averaging 115mph, and my fastest serve was that speed," she said.
"I think I did a good job of trying to find a way in the second set but in the end I just didn't have enough.
"I'm not going to let my head hang. I'm very capable of working hard and I look forward to better days."
Williams defeated Sharapova in the 2005 semi-finals, on her way to winning the third of her Wimbledon titles.