Tennis journeyman John Millman has seen plenty in his years in the game but his bizarre Australian Open win over Argentine Diego Schwartzman was a first.

Millman moved through to a second round match-up against Luxembourg’s Gilles Muller after his opponent was stretchered off suffering full body cramps.

The 26-year-old Queenslander dropped the first two sets in his first-round match but claimed the third in tiebreak.

He was leading 2-0 in the fourth when Schwartzman crouched down mid-game and called for a trainer.

The chair umpire then enforced a rarely used rule to leave the scoreboard ticking over as the distressed South American received treatment and tried to recover.

He trailed 5-0 by the time he called it quits, handing Millman only his second ever win at a major, 3-6 5-7 7-6 (7-2) 5-0.

“It hasn’t happened to me before and it was pretty awkward out there,” said Millman, the world No.92.

“I wish the best for Diego for a speedy recovery but I’ve got to now take the win and move on to round two.”

Millman said he wasn’t at his best early on but felt the crowd had lifted him and momentum had swung his way even before his opponent’s downfall.

“I played a very good tiebreaker and didn’t feel as if he was injured during that but obviously he deteriorated pretty quickly so I can’t be sure.

“I’m trying to still get my head around it.”

Millman lost his only previous meeting with world No.38 Muller 7-5 6-3 in Stockholm last year and felt with the crowd support he was a real chance.

“He got me then in two tight sets but anything’s possible here and I’ll definitely have the crowd support.

“I feel like I can go further here and win matches.”