MASON, Ohio - For Rafael Nadal, moving up to No. 1 is just a matter of time.

The 22-year-old Spaniard made a change at the top inevitable Friday by advancing to the semifinals of the Cincinnati Masters. He beat Nicolas Lapentti 7-6 (3), 6-1 for his 32nd straight win, setting up a seismic shift in the world rankings.

After three years of chasing Roger Federer, he’s about to pass him.

Nadal would take over the top spot in next week’s rankings if he wins the tournament. Even if he fails, he now has piled up enough points in Cincinnati to overtake Federer when the rankings come out on Aug. 18. The rankings include points earned in the last 52 weeks, and time is on Nadal’s side.

He knew it when he took the court, and thought about it “a little bit” during the match. When Lapentti’s forehand return sailed wide to finish off the match. Nadal joyously smacked a tennis ball and tossed his wristbands into the stands.

“It’s emotional,” he said. “I know I’m going to be No. 1. Getting No. 1 is a present for a lot of work in the past, so it’s satisfying.”

Federer was knocked out of the tournament on Thursday, jeopardizing his streak of 235 consecutive weeks atop the rankings. Nadal has been right behind him since July 25, 2005, a span of 158 straight weeks.

With two more wins this weekend, Nadal would trade places right away.

“The important thing is that I continue to play well, continue to win,” Nadal said.

He’ll play third-seeded Novak Djokovic in the semifinals on Saturday. The other semifinal matches eighth-seeded Andy Murray against Ivo Karlovic — a 6-foot-10 Croat who knocked Federer out of the tournament and opened the way for Nadal to move up.

Djokovic feels good about his overall game heading into the semifinal against Nadal. His first serve was a concern earlier in the week, but he got two-thirds of them in while beating Ernests Gulbis 6-3, 6-4.

“I thought that I was serving much better, and day after day I’m getting stronger in the segment of my game which is really important coming up to the final stages of the tournament,” Djokovic said.

While Nadal turns this week into a springboard, Murray is using the $2.6 million ATP Western & Southern Financial Group Masters to improve his ranking for the U.S. Open. For the second week in a row, Murray reached a semifinal — he also made it at Toronto before losing to Nadal.

Getting there was much tougher this time. At the start of the second set of his 2-6, 6-3, 6-1 victory over Carlos Moya, it appeared he was finished.

Murray was dominated in the opening set, then had his serve broken to start the second. Troubled by a chronically sore knee the last few weeks, Murray added to his problems by twisting the knee when he planted for one shot. He bent over in pain, leaning on his racket for support.

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“I almost hyperextended my knee a little bit,” he said. “It was a little bit uncomfortable for a few points.”

It sure looked grim. Felt that way, too.

“He was playing too well and my game was not up to scratch,” Murray said. “I just had to try and stay tough and not give up.”

Murray had only one thing left in his favor: Moya didn’t have much left.

The 31-year-old Spaniard had to play two singles matches in the heat on Thursday afternoon to reach the quarterfinals. He completed a three-set match that had been suspended by rain the previous night, rested for a couple of hours, then beat Igor Andreev in two tight sets to set up his match against Murray.

Three matches in two days was too much. By the third set, the humidity and heat — an on-court thermometer registered 98 degrees at the opening serve — got to Moya, who was hardly moving to get to shots by the end.

“He maybe got a little bit tired,” Murray said.

A day after he took out Federer by winning a pair of tiebreakers, Karlovic won two more to reach his first Masters semifinal. He served 24 aces in a 7-6 (6), 7-6 (3) victory over Philipp Kohlschreiber.

For the second match in a row, Karlovic got a victory without breaking his opponent’s serve. Instead, he relied on his dominant serve to win the tiebreakers.

“In a tiebreak, it’s most important to serve well and to use your chances,” Karlovic said. “I was playing well this week, so I’m happy about that.”