Miami:World number one Roger Federer has rolled over unseeded Jose Acasuso 7-6 (7/5), 6-2 in a fourth-round match at the $3.8 million ATP and WTA hardcourt tournament in Miami.
The top seeded Swiss star has not gone this deep into a season without winning a championship since 2000 - the last year he failed to win a title.
"It was key for me to serve well, especially in the beginning, and it was a good serving day today," said Federer yesterday. "I was very happy with it."
Winning in Miami would be nothing new to Federer, who claimed back-to-back titles at this men's and ladies' tournament from 2004-05.
The 26-year-old reached the fourth round here last year, but was upset by Guillermo Canas.
"Now I feel like I'm playing well," said Federer who faces American Andy Roddick in the quarter-finals.
"You can tell, as well, I'm moving well and playing well and serving well. That's what it comes down to for me.
"I had many matches where I came through in a close way, and that's what made me the best player for so long ... winning those big points over and over again."
Second seed Rafael Nadal, who lost to Federer in the 2005 final, also reached the quarter-finals yesterday by beating 15th-seeded Frenchman Paul-Henri Mathieu 6-4, 6-4.
The Spaniard owns a commanding 8-0 lead in the all-time series against Mathieu, who retired from their match at the Australian Open in January. Like Federer, Nadal has yet to win on tour this season.
Ninth-seeded American James Blake is through to the quarter-finals after claiming a 6-3, 6-4 win over No. 27 Radek Stepanek.
Roddick will join his compatriot in the last eight. Roddick struggled in the first set before rallying to beat unseeded Frenchman Julien Benneteau 4-6, 6-3, 6-2.
Roddick, who announced his engagement to swimsuit model Brooklyn Decker, won here in 2004 and is making his ninth-straight appearance. Roddick is facing a monumental task as he has lost 15 of his career 16 meetings with Federer.
Russia's Dmitry Tursunov failed to move through as 10th-seeded Czech Tomas Berdych claimed a 6-2, 6-2 win in their fourth-round match.
On the women's side of the draw, Svetlana Kuznetsova spoiled the prospect of an all-Williams semi-final.
Hours after Serena Williams was victorious in her quarter-final, Kuznetsova defeated Venus Williams 6-4, 6-4.
"It was pretty ups and downs for me and for her, but I guess I was more consistent and I played better," Kuznetsova said.
"I served better. I served more consistently than she. I didn't have so many aces, but I was more consistent."
The Russian held serve throughout the first set, winning all 14 of her first-serve points. Tied at 3-3 in the second set, Kuznetsova broke Williams to go up 4-3 and ended up serving out for the match.
Williams was attempting to capture her fourth title at the event, having won the tournament in 1998, 1999 and 2001.
"I just felt a little bit off," Venus said.
"I didn't have the answers today, and she played well.
"I'm always happy for Serena to win. It would have been obviously very exciting for me to win too, but it just didn't happen."
Younger sister Serena had held up her end of the bargain earlier Tuesday with a 6-2, 6-0 victory over top seed and world No. 1 Justine Henin.
Henin had won three straight in the series against Serena - claiming quarter-final victories at Roland Garros, Wimbledon and the US Open - but was outplayed by the American.
Serena, who beat Henin here in last season's championship match, captured three breaks in each set of the 80-minute match.
It was another tough loss for the 25-year-old Belgian, who was playing her first tournament since being upset by Francesca Schiavone in the quarter-finals at Dubai.
"Today I didn't make as many errors," Serena said. "I stayed positive no matter what happened. I've been practising like a champ. Today I finally started playing a little bit the way I've been practising."