Stan Wawrinka in action against Milos Raonic during their second round match on day four of the Australian Open. Photo: Julian Smith/EPA

MELBOURNE – The 2014 champion Stan Wawrinka was edged out of the Australian Open Thursday by a relieved 16th seed Milos Raonic in the tightest of second-round battles.

The 33-year-old Swiss, unseeded for the first time since his debut in 2006 after being plagued by injury, fell to the Canadian after four sets decided on tiebreaks 6-7 (4/7), 7-6 (8/6), 7-6 (13/11), 7-6 (7/5).

“That's hard to describe,” said Raonic. “I feel four hours went by in about 15 minutes. The adrenalin just takes over.”

Wawrinka was a break up in the fourth set but failed to serve out from 5-4 to take it to a fifth.

“I was fortunate to stay alive in the fourth set,” admitted Raonic, whose best Slam performance was reaching the 2016 Wimbledon final where he lost to Andy Murray.

“Four tie-breaks, three went my way,” added the Canadian. “Could easily have been different.”

Three-times Grand Slam champion Wawrinka won the Australian Open five years ago, beating Rafael Nadal in the final, but knee surgery during 2017 saw his ranking plunge to 263.

He began slowly climbing back last year and is now back to 59th in the world.

The Swiss showed more than a few glimpses of his old greatness with his powerful single-handed backhand in full cry.

And Wawrinka's serve powered down 28 aces to Raonic's 39 during four hours and one minute of blistering play.

Milos Raonic reacts against Stan Wawrinka during their second round match on day four of the Australian Open. Photo: Julian Smith/EPA
Milos Raonic reacts against Stan Wawrinka during their second round match on day four of the Australian Open. Photo: Julian Smith/EPA

The match started under cloudy skies and finished indoors after a mid-match rain delay caused organisers to close the Rod Laver Arena roof.

“I just tried to get my hand on his serve, especially with the roof open,” said Raonic. “It's how I like to go about my game, so tough to be on the receiving end.

“I do a little better indoors normally. So thank you for raining up there,” he added, looking towards the heavens.

Raonic, whose best previous Australian Open performance was a semi-final in 2016 that he also lost to Murray, will face France's unseeded Pierre-Hugues Herbert in the third round.

Agence France-Presse (AFP)