KEY BISCAYNE, Fla. -- On a sultry afternoon in the subtropics, Serena Williams sat under an umbrella and sipped a refreshment.
A day at the beach? Almost. When play resumed, Williams made the world's top-ranked woman look like a beginner, beating nemesis Justine Henin 6-2, 6-0 in the quarterfinals of the Sony Ericsson Open.
Williams won the final 10 games Tuesday by playing nearly flawless tennis, while Henin unraveled after she double-faulted three times to fall behind 4-2.
"It wasn't easy," Williams said. "It was just the fact of me making the right shots at the right time."
"I'm always happy for Serena to win," Venus said. "It would have been obviously very exciting for me to win, too, but it just didn't happen."
Venus was hurt by eight double faults, and she converted only one of six break points.
"Is that who I play?" Roddick said facetiously. He's 1-15 against Federer and has lost their past 11 meetings.
The top-ranked Federer advanced by beating Jose Acasuso 7-6 (6), 6-2.
Serena Williams' rout of Henin was a stunner, given the drama usually generated by the rivalry. Williams had lost their past three meetings, all in 2007, at the French Open, Wimbledon and the U.S. Open.
But Williams beat Henin in the Key Biscayne final a year ago, overcoming two championship points.
"I wish this was a Grand Slam," Williams said with a laugh. "I'm going to try do this at a Grand Slam and not only at this tournament."
Conditioning can be an issue for Williams, but she has never looked more agile than in the past week. No longer forced to rely on mere power, she lobbed over Henin to stay in rallies, chased down a drop shot to hit a winner and even played serve and volley.
During her post-match news conference, an exchange regarding Williams' fitness left the room in laughter.
Reporter: "So many people here at the tournament have been buzzing about just how good you look physically on the court. You've not looked this good since... Can you finish that sentence?"
Williams: "Since 1982."
Reporter: "Serious question."
Williams: "That was a serious answer."
Seeking her fifth Key Biscayne title, Williams is improving as the tournament progresses. She committed 60 unforced errors in her opening match but had only 15 against Henin.
The Belgian, meanwhile, struggled even with her signature backhand and found herself stuck at the baseline.
"I was too defensive, for sure," Henin said. "Against this kind of player, you don't have any chance if you play that game, and I didn't have really any courage to do something else. When you're on the court, it's not that easy. Now I can say it wasn't enough."
Federer, still seeking his first tournament title this year after a bout with mononucleosis, had 31 winners and only 11 unforced errors. He lost just 10 points on his serve.
"It's always nice when you feel well from the beginning on your serve," he said.
By reaching the final eight, Blake matched his best showing at Key Biscayne. He has often struggled in the event, where his career record is only 11-6, including a loss in his opening match last year.
"I definitely haven't had the best results here," Blake said. "It's one of the things I can't really explain, but this year is hopefully going to be very different."
No. 15 Guillermo Canas, last year's runner-up, lost to No. 31 Igor Andreev 6-4, 7-6 (6). No. 10 Tomas Berdych beat Dmitry Tursunov 6-2, 6-2, and Janko Tipsarevic rallied past No. 11 Mikhail Youzhny 3-6, 6-0, 6-3.