MELBOURNE, Jan. 16 (Xinhua) -- Top seed Andy Murray claimed his first win as world number one in a Grand Slam with a 7-5, 7-6(5), 6-2 victory over Illya Marchenko of Ukraine in the opening round of the Australian Open here on Monday.

The Briton, who took over the No.1 ranking from Serbian Novak Djokovic late last year, made some mistakes in the match against the Ukrainian, but eventually sealed it in three straight sets.

Murray has lost four of the last six finals here, including the previous two, to six-time champion Novak Djokovic. He admits there's one thing he desperately wants to change.

"I've never won here - I'm going to try to change that this year," he said.

Two players who could potentially stand in his way are fifth-ranked Kei Nishikori of Japan and 10th-ranked Tomas Berdych of the Czech Republic. Both had first-round wins earlier in the day.