Novak Djokovic also made the last four, beating Albert Montanes 6-2, 6-3.

Now, Rafael Nadal has to beat mentor and friend Carlos Moya later Friday to protect his No. 2 ranking in the world. If Nadal loses, Djokovic will leap over him when the new rankings come out Monday. Nadal has been ranked second for a record 147 consecutive weeks.

Federer, whose No. 1 ranking is not in danger, will play Andreas Seppi in the semi-finals. Seppi defeated Nicolas Kiefer 6-3, 5-7, 7-5. Top-ranked Federer, seeking his fifth title in Hamburg, broke Verdasco’s serve once in the first set.

Verdasco, who lost in the first round to Federer in Hamburg three years ago in their only previous encounter, had his right foot taped after taking a 3-2 lead in the second set and didn’t win another game.

“I felt a sharp pain in my ankle in the fourth game, just when I was making him suffer,” Verdasco said.

Federer has won only one title this year, at a relatively small clay-court tournament last month in Estoril, Portugal. He lost his sixth match of 2008 in the Rome Masters quarter-finals last week, to Radek Stepanek, but has eased through his first three matches in Hamburg without dropping a set.

The tournament is a major warm-up for the French Open later this month, the only Grand Slam title that Federer has yet to win. Djokovic won the last four games of the first set and the last three of the second to breeze into the semi-finals. “That was the idea, trying to finish as fast as possible,” Djokovic said.

He is seeking back-to-back titles after winning in Rome last week and also captured the first Grand Slam of the year, the Australian Open.

Paes-Robredo duo in semis

Leander Paes and his Spanish partner Tommy Robredo notched up a straight set victory over Ivan Ljubicic and Robin Soderling to storm into the doubles semi-finals of the Hamburg ATP Master Series.

The unseeded Indo-Spanish pair won 6-2, 7-6 (3) after the 72 minute contest to set up a semi-final clash with second seeded duo of Canadian Daniel Nestor and Nenad Zimonjic of Serbia. in the pre-quarterfinals.