Swiss third seed Stanislas Wawrinka outlasted tiring former champion Juan Martin del Potro in four sets to advance to the semi-finals of the US Open on Wednesday.
Twice Grand Slam winner Wawrinka ended the rousing comeback effort by the Argentine at Flushing Meadows with a 7-6(5), 4-6, 6-3, 6-2 win to close out Day 10 at the year's last Grand Slam.
Del Potro, the 2009 winner, had missed nine successive Slams due to a string of wrist surgeries before returning to Wimbledon, where he ousted Wawrinka in the second round and went on to claim silver at the Rio Olympics.
Wawrinka, the 2014 Australian Open winner and 2015 French Open champion, will next meet sixth seed Kei Nishikori of Japan, the 2014 Flushing Meadows runner-up, who upset world number two Andy Murray in five sets in their quarter-final.
Friday's other men's semi-final will pit world number one Novak Djokovic against French 10th seed Gael Monfils.
