Dubai - Novak Djokovic needed a piece of luck against a close friend before maintaining his unbeaten 2012 sequence of ten matches and carrying his bid for a record fourth straight Dubai Open title into the semi-finals.
The triple Grand Slam titleholder beat the seventh-seeded Janko Tipsarevic 6-1, 7-6 (8/6) on Friday but only escaped from set point down at 5-6 in the tie-breaker thanks to a double fault from his fellow Serbian Davis Cup hero.
It earned Djokovic another meeting with Andy Murray, the triple Grand Slam finalist from Scotland, against whom he survived a sensational five-hour semi-final in Melbourne.
"It was very tense, especially towards the end," said Djokovic.
"He had his chances. We both got nervous and made unforced errors and double faults at the end, but I manage to stay composed and got through, so I'm happy."
For a while it looked as though he would win comfortably against Tipsarevic, with whom he had "practised a million times".
Djokovic hit with great power off the ground, moved superbly, and won the first set in only 27 minutes.
He began to run into difficulty after he was unable to convert break points at 30-40 in both the fifth and seventh games of the second sets.
Tipsarevic began to strike the ball more boldly, won many of the longer rallies with his tenacious base-lining style, and got the support of the crowd behind his fight-back.
Djokovic meanwhile appeared to grow a little more inhibited, and when he went 0-3 and 1-4 down in the tie-break a deciding set looked very possible.
But after Tipsarevic delivered his crucial double fault, Djokovic capitalised with a wicked backhand slice which earned him another point against the serve, and followed it with a winning combination of a good serve and an unstoppable forehand drive.
Asked what to expect from a re-match with Murray, Djokovic said: "another thrilling match."
He added: "We played many exciting ones in the last couple of years.
"We are the same age and grew up together and the first time we played each other was at the age of 11. Hopefully we will play another great match."