World number one Roger Federer [Images] was in cruise control on Thursday night as he beat Belgian Olivier Rochus 6-3, 6-4 to lead four of the world's top five into the quarter-finals of the Cincinnati Masters.

Lleyton Hewitt [Images], Marat Safin [Images] and Andy Roddick [Images] all moved into the last eight but Federer was the star of the show as he overcame a ragged start to set up a clash with Argentine Jose Acasuso.

After spraying a few forehands over the baseline in the first few games, Federer, playing his first event since Wimbledon [Images], found his rhythm and Rochus, the world No 34, could only laugh as shot after shot was sent ripping past him.

The top seed smashed 14 aces and broke in the eighth game of the first set and the third of the second as he advanced in style.

"I'm really happy with the way I played tonight," Federer said.

"He's a really tough player and I played aggressive which you have to do against him because he's so good from the baseline."

Federer and Rochus played each other many times in the junior ranks, and the Swiss admitted he had not always had things his own way.

"We played under 14s when he was good and I was not," Federer said. "When we got to under 16s I started to grow and started to win a bit more."

Fourth seed Marat Safin was the best of the rest as he hammered Slovakia's Dominik Hrbaty 6-0, 6-3.

Also appearing in his first tournament since Wimbledon, the Russian was at his imperious best as he stormed through in 68 minutes to set up a meeting with American wildcard Robby Ginepri, who beat Spaniard Carlos Moya [Images] 6-3, 6-4.

Hrbaty held a 7-6 advantage over Safin in their head-to-heads but once the Russian held serve in a tight first game, he was in complete control.

"It was much better today," said Safin, who dropped a set in beating British wildcard Andy Murray [Images] in the previous round.

"In the second set I was a little bit nervous because I was playing too good, and I almost lost the second set."

Safin said his left knee injury, which kept him off the tour for seven weeks, is still causing him pain but he is satisfied with his form.

"It's a little bit too early to say that I'm getting closer to my best shape," he said.

"But at least I'm fighting. It's not like I'm playing the most unbelievable tennis -- I'm struggling to win some shots. But basically I'm hungry and I'm still there."

SERVED BETTER

Third seed Hewitt, who battled past Greg Rusedski [Images] in three sets on Wednesday, raced to a 5-0 lead against Croatian Mario Ancic and one break in the second set was enough for victory as he claimed a 6-1, 6-4 win.

"I really struggled with my serve yesterday against Rusedski," Hewitt said. "But I served much better today."

The Australian retired from his first-round match in Montreal last week with a stomach virus but said he is improving all the time.

"The first couple of matches I was feeling a bit scratchy but I'm getting better and better every day," he said.

He'll meet Russian sixth seed Nikolay Davydenko [Images], who beat unseeded Chilean Fernando Gonzalez [Images] 6-3, 6-4.

Fifth seed Roddick, who had scrambled past Spaniard Juan Carlos Ferrero [Images] in the previous round, was pushed hard by Argentine Juan Ignacio Chela before progressing with a 7-6, 6-2 victory.

The American saved a break point at 4-4 before winning the opening-set tiebreak and then broke twice in the second set to set up a meeting with Russian Mikhail Youzhny, who beat French wildcard Gael Monfils 4-6, 6-1, 6-1.

"I needed to get some matches in and I feel like I am competing well," Roddick said.

"I tried to be more aggressive today, make him scared of my forehand. I still think there's room to improve but I am playing well."

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