Novak Djokovic defeated Serbian compatriot Janko Tipsarevic 6-1, 7-6 (6) on Thursday and set up a Dubai Open semi-final with Andy Murray.
Roger Federer is scheduled to face Juan Martin del Potro in the other semi at Aviation Club.
Murray advanced by beating fifth-seeded Tomas Berdych 6-3, 7-5. Federer had another routine quarter-final, beating Mikhail Youzhny 6-3, 6-4.
Del Potro ousted Jo-Wilfried Tsonga 7-6 (1), 6-2 for the second time in two weeks.
The top-ranked Djokovic, gunning for his fourth Dubai title in a row, broke Tipsarevic twice in the first set. The No. 9-ranked Tipsarevic came to life in the second set, holding his serve throughout and taking a 4-1 lead in the tiebreaker. Tipsarevic missed a set point at 6-5 when he double-faulted and Djokovic won the next two points.
“It’s always difficult, I guess, for both of us. We know each other really well,” Djokovic said. “We both got a little bit nervous toward the end, I guess, and it was just luck to prevail.”
Murray had lost his last three matches against Berdych, but broke early to take control of the first set.
In the second, the players twice traded breaks of serve. Murray broke to go up 6-5, but squandered six match points before clinching it when Berdych hit long.
Berdych had a chance to break to take the second set to a tiebreaker. A Murray serve was initially called out, but overturned on review. Umpire Mohammed Lahyani gave the point to Murray, leaving Berdych angry because he felt the point should have been replayed.
Lahyani argued that Berdych had already played his return into the net when the call came.
Murray said he was looking forward to his semi-final against Djokovic.
“I would like to get a chance to play him again,” Murray said. “Before the Indian Wells-Miami stretch it would be good to see exactly what I need to work on, where my game is. I had a great match with him in Australia, and hopefully I can reverse the result tomorrow.”
The Serb leads their matchups 7-4, including a five-set semi-final at the Australian Open.
Looking for his fifth Dubai title, Federer beat Youzhny for the 12th straight time.
With his serve working as well as it has all week, the second-seeded Federer again won without losing a set.
“I thought, again, on my serve I was doing many of the right things,” said Federer, who had five aces and won 80 percent of the points on his second serve.