Djokovic reaches eighth final; will face del Potro

NEW YORK » Novak Djokovic served impeccably and used his usual brand of court-covering defense to reach his record-tying eighth U.S. Open final by beating Kei Nishikori 6-3, 6-4, 6-2.

Djokovic missed the tournament last year because of an injured right elbow that eventually required surgery. But he is back to his best as he bids for his third title at Flushing Meadows and 14th Grand Slam trophy overall.

He will face 2009 champion Juan Martin del Potro in Sunday’s final.

Del Potro advanced when defending champion Rafael Nadal retired from their semifinal Friday because of a painful right knee after dropping the opening two sets. Nadal is the first man to retire from a semifinal or final at the U.S. Open since the professional era began in 1968.

Nadal stopped playing after dropping the opening two sets, putting del Potro back in a Grand Slam final for the first time since winning the 2009 title.

“That was not a tennis match at the end. Just one player playing, the other staying on one side of the court,” Nadal said. “I hate to retire, but staying one more set out there, playing like this, would be too much for me.”

Del Potro was leading 7-6 (3), 6-2 after two hours of play when Nadal shook his head and said he had to stop.

“Of course, it’s not the best way to win a match,” said del Potro, who hugged Nadal when it was over.