Djokovic moves on to U.S. Open semifinal

NEW YORK – Locked in a taut, thrill-a-minute second set, Novak Djokovic and Juan Martin del Potro headed to a tiebreaker and promptly produced a 20-stroke masterpiece of a point befitting a pair of past U.S. Open champions.

More than a dozen shots in, defending champion Djokovic tossed up a lob. Del Potro, the 2009 champion, sprinted with his back to the court, got to the ball and lofted a lob the other way. Djokovic slammed an overhead. Del Potro somehow kept the ball in play. Djokovic laced a drop shot. Again, del Potro got there, attempting another lob. It landed long.

A point from a two-set lead, Djokovic threw his head back, roared “Come on!” and pumped his arms. Del Potro leaned his elbows atop the net, hunched over and rested his head on his arms.

Close and compelling as their quarterfinal was, it might as well have been over. Djokovic’s down-the-line backhand winner moments later ended the tiebreaker, gave him a commanding lead, and sent him on the way to a 6-2, 7-6 (3), 6-4 victory Thursday night that put him in his 10th consecutive Grand Slam semifinal.

“We played some incredible rallies and incredible points,” Djokovic said. “It’s always entertaining, always so much fun, playing in these night sessions.”

The second-seeded Serb will face fourth-seeded David Ferrer of Spain on Saturday, with a spot in Sunday’s final at stake. Ferrer advanced to his fourth career major semifinal by using his high-energy brand of leg-churning, ball-chasing tennis to outlast eighth-seeded Janko Tipsarevic of Serbia 6-3, 6-7 (5), 2-6, 6-3, 7-6 (4) in 4 hours, 31 minutes.

Under the lights at night in Arthur Ashe Stadium, the showcase matchup of Djokovic’s squeaky-sneaker defense, reflex returns and line-catching groundstrokes against the seventh-seeded del Potro’s big-as-can-be forehands topping 100 mph lasted a few minutes past three hours. But it was tremendously good every step of the way, and the second set alone was 84 minutes long – 11 minutes more than Djokovic’s entire first-round match last week.

These are the only two men who have managed to beat Roger Federer, owner of a record 17 major trophies, and Rafael Nadal, owner of 11, in the course of a single Grand Slam tournament.