World number one Novak Djokovic survived a rocky start to defeat Grigor Dimitrov 7-6 (7-4), 6-1 and reach the fourth round of the Indian Wells ATP Masters and WTA tournament.

Djokovic, unbeaten in a 2013 campaign that so far includes a fourth Australian Open title and an ATP triumph in Dubai, was on the ropes in the opening set against the 21-year-old Bulgarian, who raced to a 4-1 lead and served for the set at 5-3.

But Dimitrov served up four double faults in the ninth game and was broken, and that was the only opening that Djokovic needed.The Serbian star battled back to win in 67 minutes. He raced to a 5-0 lead en route to winning the first-set tiebreaker and didn’t face a break point in the second.

Djokovic wrapped it up with a love game, sealing the victory with a service winner on match point.“It was not really a beautiful match to watch,” said Djokovic. “There were a lot of unforced errors, and we both looked quite sluggish on the court, very slow.”He will now face Sam Querrey in the fourth round, who edged Australian Marinko Matosevic 7-6 (7-5), 6-7 (7-9), 7-5.

In another match, third seed Andy Murray displayed much sharper form than Djokovic as he overcame Lu Yen-Hsun 6-3, 6-2 to avenge his defeat to the Taiwanese in their first-round 2008 Beijing Olympics meeting.