Djokovic defuses 'gutsy' Lopez to reach US Open semis

World number one Novak Djokovic battled past his Spanish opponent Feliciano Lopez in thrilling four sets to progress through to the US Open semi-finals.

The Serbian overcame 18th seed Lopez 6-1, 3-6, 6-3, 7-6 (7/2) in sweltering conditions at Flushing Meadows.

Although the eight-time Grand Slam champion produced a dominant performance to secure the first set, Lopez fought back stoutly to take the next set.

A furious Djokovic then bounced back to take the third set and played the perfect tie-breaker in the fourth to take victory, Sport24 reported.

Djokovic will next face reigning US Open champion Marin Cilic, who claimed a hard-fought 6-4, 6-4, 3-6, 6-7 (3/7), 6-4 win over France's Jo-Wilfried Tsonga, in semis.