NEW YORK (AP) -- Playing terrific defense and catching lines with his shots all night long, defending U.S. Open champion Novak Djokovic beat 2009 champion Juan Martin del Potro 6-2, 7-6 (3), 6-4 on Thursday to reach the semifinals at a 10th consecutive Grand Slam tournament.
The showcase matchup was compelling throughout, and closer than the scoreline indicated. The thrilling second set lasted 84 minutes -- 11 more than Djokovic's entire first-round victory last week.
The second-seeded Serb will face fourth-seeded David Ferrer of Spain on Saturday. 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.