By Sarah Holt
BBC Sport at Wimbledon
Serena Williams kept her title defence firmly on track with a dominant 6-1 6-1 victory over fellow American Jennifer Capriati.
Willliams is bidding for her third straight Wimbledon crown
The top seed looked back to her best on Centre Court as she inflicted a treble break on the seventh seed to race to the opening set.
Williams did not drop her tempo and despite swapping breaks she eased past a jaded Capriati in 45 minutes.
The 22-year-old faces French fourth seed Amelie Mauresmo in the semi-finals.
"Amelie plays very well on grass so I'm looking forward to playing her again," said the top seed.
"I love her game and I think it'll be a great match."
Williams is bidding to become the first woman since Steffi Graf to win three straight Wimbledon titles.
"I've been thinking about that since the beginning of the tournament," Williams told BBC Sport.
"I was very focused coming out here and I have some goals.
"But I'm just happy to be in the semis after a big injury (knee) so it's really exciting for me."
Capriati swept past Williams in the quarter-finals of the French Open earlier this month but she struggled to find that kind of form on Wimbledon's grass courts.
"I didn't have much of a chance to get into the match and play," said the 28-year-old.
"I felt so much pressure from her on the baseline and I really think that was the best she's ever played against me."
Mauresmo booked her place in the last four with a powerful 6-0 5-7 6-1 win over Paola Suarez.
The Frenchwoman was too strong for the ninth seed early on and only lost six points on her serve in a 22-minute first set.
However, the Argentine got her game together and started to put the Mauresmo serve under pressure to take the match into a decider.
Mauresmo responded by cutting out the unforced errors and broke Saurez three times, sealing victory with a fierce forehand.
"It feels great to be in another semi-final," said the fourth seed.
"I had some trouble in the second set and got scared a little but I got much better in the third."