Novak Djokovic of Serbia
Novak Djokovic of Serbia celebrates defeating Feliciano Lopez in their quarterfinal match at the U.S. Open Championships tennis tournament in New York, September 9, 2015. Reuters/Carlo Allegri

Novak Djokovic of Serbia was frustrated in a second set loss but recovered just in time to beat Spanish challenger Feliciano Lopez in four sets, 6-1 3-6 6-3 7-6 (2). The World No. 1 advanced to the next round where he will face defending champion Marin Cilic of Croatia.

“Just frustrating when you drop -- you play one sloppy service game in the beginning. Was 30-Love in that game and I allowed him to break me and the set was gone,” Djokovic said post-match via the tournament’s official website.

“I thought I played a pretty good first set, and then after that, you know, I was just trying to hang in there and wait for the opportunities. I played good beginning of the third. Fourth was anybody's game, really. Didn't have many chances on his service games. Played a very good tiebreak. That's a positive.”

Lopez fired more aces in the match, 14-9 but the Spanish player just converted just once on six break opportunities. Djokovic’s consistency was on display as well with just 17 unforced errors compared to Lopez’s 48.

Djokovic is a perfect 13-0 in his head-to-head meetings with Cilic but said that the Croatian feels confident at this stage owing to a couple of five-setters in previous matches and because he has won his first Grand Slam title last year. Djokovic is also 4-0 against Cilic in the majors.

The Serbian beat the Croatian twice in Wimbledon, in 2014 and 2015 and once each at the US Open in 2008 and French Open in 2014.

Overall, Djokovic has lost just two sets in the 2015 US Open, one in the previous round and the other one in the quarterfinals against Lopez.

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