US Open: Novak Djokovic survives Lopez's big volleys to reach semi-finals

Top seed Novak Djokovic was tested by net-charging Spaniard Feliciano Lopez in a duel of volleys and passing shots before booking a berth in the semi-finals of the US Open in the wee hours of Wednesday.

On a hot, humid night at Flushing Meadows, Djokovic waged an entertaining battle with the 33-year-old serve-and-volleyer, before finishing off the 18th seed 7-2 in the fourth set tiebreaker to complete a 6-1 3-6 6-3 7-6(2) victory.

Lopez won 28 of 41 serve-and-volley points, while Djokovic countered with 33 forays to the net that produced 19 points for the world number one.

"He's one of the rare players who actually serves and volleys after the first and second serves," said Djokovic, winner of this year's Australian Open and Wimbledon championships. "He's got a very big serve."

Lopez served up 14 aces, while Dojokovic registered nine.

"It was anybody's game in the fourth set," the Serb said. "I'm just glad to get through in four."

Djokovic, 61-5 with six tournament titles this season, will face defending champion Marin Cilic of Croatia in the semi-finals. The ninth-seeded Cilic advanced with a five-set win against France's Jo-Wilfried Tsonga. 

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