Federer and Roddick reach Miami Masters quarters

Swiss world number one Roger Federer and American fourth seed Andy Roddick safely negotiated fourth round matches at the Miami Masters Series event on Tuesday.

Federer cruised past unseeded Russian Dmitry Tursunov 6-3 6-3 in only 58 minutes, but former world number one Roddick needed 93 minutes to oust German qualifier Simon Greul 6-3 3-6 6-2.

Federer will next face American James Blake, who defeated Argentina's Juan Ignacio Chela 4-6 6-1 6-0.

It is a repeat of the Masters Series final in Indian Wells last Sunday, won by Federer.

Tursunov, 23, had never faced Federer before but learned quickly why the "Federer Express" is the defending champion and won January's Australian Open.

Federer won his 45th consecutive match in the United States and 21st Masters match in a row.

"I always feel like it's more difficult to play somebody you haven't played," Federer said. "We also haven't practiced, so you never get to know where he serves on big points and stuff like this.

"But I feel I did very well. He's a very dangerous player and I really had to play a solid game, and I thought I did, so I'm pleased."

Roddick, who fired nine aces and won 86 percent of his first-serve points, qualifies for a quarterfinal against Spain's David Ferrer, who eliminated Belgian Olivier Rochus 6-7 7-6 7-5

Roddick, who has reached only one semifinal in a disappointing year, took the first set in 29 minutes, promptly lost the second, but dominated the decider, breaking Greul in the second game on his way to victory.

"If I would have let it go a little further in the third set, he would have had a lot of momentum and it would have been tough for me," Roddick said.

Greul had earlier ousted Thailand's Paradorn Srichaphan, Slovakia's Dominik Hrbaty and Britain's Tim Henman, who blitzed the 25-year-old from Stuttgart in the first set only to drop the last two.

Two Croatians also won fourth-round matches. Sixth seed Ivan Ljubicic defeated Belgian Christophe Rochus 6-3 6-1 and Mario Ancic eliminated Russian fifth seed Nikolay Davydenko 7-5 6-4.

Third-seeded David Nalbandian of Argentina will face Ancic after beating Czech Radek Stepanek. Argentina's Agustin Calleri will play Ljubicic after downing Nicolas Kiefer of Germany 3-6 6-3 7-5.

In the WTA event at the same venue, women's world number one Amelie Mauresmo of France dispatched fifth-seeded Russian Nadia Petrova 6-, 6-1 to book a semifinal date with Russia's Svetlana Kuznetsova.