CINCINNATI: Two-time winner Roger Federer and reigning champion Andy Murray lined up a top-two semi-final showdown at the Cincinnati Masters.

Federer, the world number one and top seed, never faced a break point as he dismissed former world number one Lleyton Hewitt of Australia 6-3, 6-4.

It was his 13th straight victory over Hewitt, and the 200th Masters series match win of Federer's career.

He fired 11 aces past the Aussie, a two-time Grand Slam winner who is still fighting to regain his top form after hip surgery last year.

Third-seeded Murray, who seized the world number two ranking en route to capturing the Montreal Masters last week, rallied to beat French lucky loser Julien Benneteau 4-6, 6-3, 6-1.

The fight eventually drained away from the 55th-ranked Frenchman after a marathon rally in game three of the second set - which ended when a Benneteau overhead caught the tape and kicked wide.

"That unbelievable rally, 53 shots or something, that really changed the match for me," said Murray. "Physically he was struggling a little bit after that."

Murray added: "I served terrible in the first set - six doubles. The ball was blowing all over the place.

"I was hitting the ball really clean from the back of the court but leaving a lot of balls short so I ended up doing a lot of running, which wasn't really the plan going into the match."

Federer and Murray will meet for the ninth time, and the Scot is one of the few players who can boast a commanding head-to-head record against the mighty Swiss.

Federer beat Murray in the US Open final last year, but Murray has won all four of their meetings since, including two this year.

Federer said Murray's new No.2 status wouldn't make a difference, but Murray's growing pile of credits might.

"He's getting up there in the tournament count, and that makes it more exciting to play a player like him, especially him being on a run like he's on right now after winning in Montreal," Federer said. "It's definitely a good matchup."

Federer is vying to add to the Cincinnati titles he won in 2005 and 2007, while Murray is seeking a second straight after beating Serbia's Novak Djokovic in the final last year.

Rafael Nadal the world number three and second seed, beat unseeded Czech Tomas Berdych 6-4, 7-5 to set up a semi-final rematch with fourth-seeded Djokovic.

Djokovic, who ousted Nadal in last year's semis here, beat ninth-seeded Frenchman Gilles Simon 6-4, 7-5.

"I'm improving every day a little bit more," said Nadal, who was sidelined for more than two months after the French Open with tendinitis in both knees.

"This was a very good win for me. When I arrived here, I didn't expect to be in (the semi-finals). Being in the semi-final is perfect for me. It will make me more confident for the US Open."