Defending Australia Open champion Roger Federer survived a major scare against Frenchman Gilles Simon in Melbourne before prevailing 6-2 6-3 4-6 4-6 6-3.

For the first two sets, Federer looked imperious from the back of the court and at the net.

His only blip in the first two sets was dropping serve midway through the second, although he still comfortably took the set to take a comfortable lead.

But Simon grew in confidence and aggression, breaking Federer’s serve twice in the first three games of the third set.

The fourth set was tighter as games stayed on serve until 4-4, when Simon clinched the decisive break with a vicious forehand winner from a Federer second serve, then saved a break point before serving out the set to level the match.

The strain of the occasion was evident in Federer in the final set, as he screamed in triumph when he won big points.

His big-match temperament came to the fore as he gained the vital break to go up 4-2, then powered through his next service game.

But the fight was not over as Simon saved four match points before Federer clinched it on his fifth with an ace.

“You think ‘I hope Gilles doesn’t play so well in the fifth’,” Federer said after the match. “You hope he gets tired because didn’t he play Sydney and come here badly prepared? Shouldn’t he be missing a bit more?”

“I remained positive and said, ‘I’ve worked hard my entire life, it’s got to pay off.’ Today I got lucky, I’m glad I won and I’m still in the tournament.”