Djokovic to face Del Potro again, Federer wins

(Reuters) - World number two Novak Djokovic has a shot at revenge against Juan Martin del Potro, who ended the Serb's medal hopes at the London Olympics, when the two clash in the Cincinnati Open semi-finals on Saturday.

World number one Roger Federer, who dealt with American Mardy Fish 6-3 7-6 in some style, will play his Swiss Davis Cup team mate Stanislas Wawrinka in the other semi.

Djokovic, who lost to former U.S. Open winner Del Potro in the Olympic bronze medal match less than two weeks ago, enjoyed a routine 6-3 6-2 victory over 12th seeded Croatian Marin Cilic on Friday to advance.

"It was my best match so far here in this tournament and came in the right moment, really," Djokovic, who had an easy passage through to the last eight after Russian Nikolay Davydenko retired injured during their match, told reporters.

"I had the biggest challenge today with Cilic who has been playing well the last couple of months and I played a really good match."

The five-times grand slam winner may have added incentive on Saturday given Serbia's Davis Cup semi-final loss to Argentina last year in which Djokovic retired against Del Potro.

"All these losses made me stronger and, yes, they are difficult, especially when you're playing for a country and when you're in Olympic Games and we're fighting for bronze medal," said Djokovic.

"He won that match. It happens. It's a sport. You lose, you win, but the most important thing is to try to move on and become even better and even stronger from those experiences and try to win."