Melbourne: Andy Murray ground out a hard-earned straight sets win over plucky Illya Marchenko to open his campaign for a first Australian Open title in Melbourne on Monday.

The world number one, who has lost five Australian finals — four of them to his key rival Novak Djokovic — carved out a 7-5, 7-6 (7/5), 6-2 victory in 2hr 47min on Rod Laver Arena.

It was an unforgiving physical workout for the British top seed, who fought back after a wobbly beginning to wear down his 93rd-ranked Ukrainian opponent in draining heat.

Murray will take on Russian qualifier Andrey Rublev in the second round.

The world number one began shakily with three double faults and along with an unforced forehand error he dropped his opening service game.

Murray broke back and appeared to be getting into the groove to be serving for the set at 5-3, but Marchenko reeled off two winning passes to break his serve.

The Scot sat in his chair fuming at he changover repeatedly saying ‘shocking, shocking stuff’ directed to his player’s box across the court.

He finally wrapped up the opening set in 55 minutes after breaking the Ukrainian’s serve at 6-5.

But a sign of his frustration was that his serve was broken in three of his first eight service games.

Murray needed 76 minutes to claim a tiebreaker and forge a two sets to nil lead in a very physical encounter with Marchenko before grabbing a double break off the wilting Marchenko to take charge of the deciding set and storm to victory.