Defending champion Marin Cilic of Croatia battled past Kazakhstan's Mikhail Kukushkin to reach the fourth round of the US Open.
Cilic claimed a 6-7 (5-7) 7-6 (7-1) 6-3 6-7 (3-7) 6-1 victory after a marathon four hours and 16 minutes.
"It wasn't easy but I stayed together and got it done," said the Croat.
Kukushkin had already accounted for 17th seed Russian Gregor Dimitrov in reaching the third round, and delivered another impressive performance on Friday.
After losing the first set, Cilic battled back superbly against a very competitive opponent to take the next two, and even found himself a break up in the fourth.
But Kukushkin wasn't done yet. He regained his lost break to force a tie-break, which he won convincingly to level the scores at two sets apiece.
Despite having the momentum on his side, Cilic hit back emphatically in the final set, breaking serve in the second game and taking full advantage of a couple of unforced errors from Kukushkin in the fourth game to seize a second break.
This time, Kukushkin couldn't battle back, and Cilic wrapped up the victory to set up a fourth round clash with either Jeremy Chardy or David Ferrer.
Also advancing early on Friday were Frenchmen Benoit Paire and Jo-Wilfried Tsonga.
Paire knocked out 26th seed Tommy Robredo 7-6 (7-3) 6-1 6-1, while 19th Tsonga defeated Sergiy Stakhovsky 6-3 7-5 6-2.