Novak Djokovic fended off a fading Andy Murray 7-6 (1), 6-7 (1), 6-2, 6-4 in a matchup of past U.S. Open champions to reach the tournament's semifinals for the eighth consecutive year.
It took a while for the No. 1-ranked and No. 1-seeded Djokovic to push himself out front in a well-played, back-and-forth, 3-hour, 32-minute match that ended after 1 a.m in New York.
Djokovic broke the eighth-seeded Murray to go up 3-1 in the third set, then fended off a pair of break points in the next game.
On the first, Murray sailed a backhand long to end a 28-stroke point, then leaned over and put a hand on his knee.
On the second, he dumped a forehand into the net, then slammed his racket against his right thigh and yelled.