Should Murray win that match, world number one Roger Federer is a potential quarter-final opponent this time around.

And he will hope to be in calmer frame of mind for his next match, having frequently lost his temper against Karlovic.

"I was disappointed with my attitude during the match, I was getting really angry and I haven't done that this year," said Murray.

"I was just in a bad frame of mind and you can sometimes snap out of it, but when you're playing someone who is as frustrating to play against as him, it's difficult.

"I was just happy with the way I came through in the end because I was not focusing as well as I should have been."

Murray took his chances well against the 6ft 10in Karlovic, converting four of his five break-point opportunities.

That came despite a sloppy start which saw the 20-year-old drop serve in game three.

He got back on level terms in game six before edging the tie-break on his third set point.

The second set followed a similar pattern, with Karlovic racing into a 3-0 lead before Murray pegged him back at 5-5, but this time it was the Croatian who bossed the tie-break.