Defending champion Roger Federer [Images] is one of four Grand Slam winners bidding to secure a semi-final spot on men's quarter-finals day at Wimbledon [Images] on Wednesday.

Set for a collision course in the next round, Federer and 2002 winner Lleyton Hewitt [Images] both meet claycourt specialists in a last eight which includes a record three native Spanish speakers.

Bidding to win his third consecutive title 23-year-old Swiss Federer takes on Chilean Fernando Gonzalez, who is yet to drop a set on the famous grass courts this year.

Gonzalez has been in remarkable form despite having limited opportunities to practice on the surface in his home country.

"Sometimes I practice on the football pitch," he said. "They put up a net, and I practice on the synthetic grass."

In their four previous meetings, Federer has never tasted defeat and is understandably confident this time around.

"Grass should favour me ... He's always got good shots. I'm looking forward to playing him," he said.

Despite not hitting his formidable best yet this year, Federer has extended his run of wins on grass to 33 matches and is determined to come away at the end of the week with the title.

"My goal for this year is Wimbledon, number one in the world. I'm right in it now. I have to prove it -- to myself especially."

Hewitt, attempting to repeat his 2002 victory here, meets Spain's Feliciano Lopez, who he beat in last year's US Open [Images] in their only meeting to date.

The 24-year-old Australian has been keeping a keen eye on the 26th seeded Spaniard since then.

"His serve and his forehand are his two big weapons," he said. "He's got a good slice backhand as well and he moves pretty well for a big guy."

"I've basically got to play him on my game against his out there and work on the weaknesses of his game and try and exploit that."

After victories over two teenagers, the other remaining Spanish speaker David Nalbandian faces an entirely different prospect.

The 2002 finalist now takes on the oldest man left in the men's draw, the 30-year-old former Australian Open [Images] champion Thomas Johansson.

PRACTICE PARTNER

Still striving for his first Wimbledon title, number two seed Andy Roddick [Images] will be all too aware of the danger his opponent poses when he takes on practice partner Sebastien Grosjean.

The 2003 US Open champion knows he faces a difficult task against Grosjean but thinks this could be his year.

"He's proven that he's one of the top five grass courters in the world," he said. "That's definitely tough to deal with. But I feel like I'm playing pretty well. I feel confident."

"Obviously it's tough when you're competing every day to try to rip each other's heads off in practice, as well. But, you know, practice is practice. It's a different thing when you got people and something on the line."

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