Novak Djokovic defeated Feliciano Lopez 6-1 3-6 6-3 7-6 (7-2) to reach the US Open semi-finals, a 21st last-four spot in his last 22 grand slams.
Top seed and 2011 champion Djokovic will face defending champion Marin Cilic in Friday’s semi-finals.
Cilic reached the semi-finals with a 6-4 6-4 3-6 6-7 (7-3) 6-4 win over France’s Jo-Wilfried Tsonga.