Miami - Andy Murray edged closer to a world number 3 ranking as he became the only man on the ATP to earn three titles this season through a 6-2, 7-5 defeat of Serb Novak Djokovic on Sunday at the Miami Masters.

The rapid-fire win in one hour, 42 minutes added the Masters 1000 honour to Doha and Rotterdam titles won since January by the 21-year- old Scot.

Murray now stands 26-2 on the season as he prepares for a quick turnaround on clay, with Monte Carlo starting April 12.

Murray owns victories in three of his last five starts at the elite Masters level, winning Cincinnati and Madrid back-to-back last season and playing the Indian Wells final against Rafael Nadal a fortnight ago.

"I'm competing on the world stage and try to improve my ranking," Murray said. "The clay season will be very important for me. On clay my game has not been the same as the top guys. I need to improve my game on clay."

The world number 4 is fast-closing on Djokovic after claiming the 11th title of his career.

Only 170 computer ranking points separate Murray from Djokovic. The Scot will drop a mere 520 points between Monte Carlo starting next weekend and Roland Garros, while Djokovic is losing 2,800 points in the same period.

"I was the biggest enemy to myself. I was struggling again and adjusting to the heat," said Djokovic, 2008 Australian Open winner. "I'm not really satisfied with the way I played today."

Murray dominated the opening set in 33 minutes, putting it away on his second opportunity as he pushed across an easy overhead.

Djokovic began to feel the heat at the start of the second set after committing 16 unforced errors in the first. The Serb lost serve in the opening game, then called for a visit from the trainer.

Told that nothing could be done about his discomfort with the spring heat, he soldiered on, breaking Murray for the first time in the afternoon for 1-all.

"That's just the way it is. I can't fight it, it's been this way for awhile," said the Serb who has withdrawn ill during matches at three of the four Grand Slams.

Djokovic's spirits rose with the scoreline as the third seed claimed a 4-1 lead before Murray responded. The Scot saved a pair of Djokovic set points in the ninth game, with the Serb double-faulting on the second.

After levelling at five games apiece, Murray regained the game that took him through the first set, breaking for 6-5 and ending the afternoon in first net point and the 43rd unforced error from Djokovic.

"It was hot out there," said Murray.

"I was a bit out of breath, but I could look at the other end and see Novak was struggling. That makes a big difference mentally. He's been struggling with the heat more this year. I've seen him play four-five hours at the US Open in these conditions. But he's still a great player." dpa