Juan Martin del Potro became the first major casualty of the men’s singles draw at the Australian Open, when he was beaten in five sets by Spaniard Roberto Bautista Agut in a match finishing at 1:20am local time.

Bautista Agut, world number 63, lost the first set against his fancied opponent, but bounced back and took the match 4-6 6-3 5-7 6-4 7-5 in three hours and 53 minutes.

Del Potro had entered the tournament in excellent form after taking out the Sydney International last week against Bernard Tomic.

Earlier, World No.4 Andy Murray compiled a stunning run of points to surge into the third round.

Murray trailed 5-1 in the third set of his match against French qualifier Vincent Millot and then won 23 consecutive points to take the match 6-2 6-2 7-5.

The Scotsman is on the comeback trail after back surgery in September but with each match is growing as a threat for the title.

He cruised through the opening two sets, with Millot troubled by a calf injury late in the second.

The Frenchman, ranked 267, had an injury time-out and was treated by a physiotherapist.

It appeared to do the trick as while he lost that set, he came out firing in the third and broke the Wimbledon champion twice to charge to a 5-1 lead.

That sparked Murray, who showed his class to level at 5-5 before wrapping up the match.

Murray said he was thrilled to be back in Melbourne where he has been a three-time finalist, losing last year to Novak Djokovic.

“I love this tournament and I’ve been in the final three times so I’m going to do my best to win it,” he said.