MELBOURNE, Australia — Canadian Milos Raonic is out at the Australian Open.

The 22nd seed in the men's tournament, Raonic was stunned by unseeded Lukas Lacko of Slovakia 6-7 (5), 7-5, 6-4, 7-6 (4) on Tuesday in the first round of the Grand Slam event.

The Thornhill, Ont., product is coming off an injury-filled season that saw his ranking drop to No. 24 from a career-high of No. 3 in 2016.

Raonic missed last year's U.S. Open after undergoing wrist surgery. He returned to the tour for one tournament in Japan in October, but retired from his quarterfinal match. He has been among the most vocal proponents for shortening the nearly year-long tennis schedule to protect top players from injury.

Raonic is a former Wimbledon finalist and has reached at least the quarterfinals at Melbourne Park the last three years.

It's only the third time that Raonic has lost in the first round of a major. Raonic also lost in the first round of the 2010 US Open and the 2011 French Open.

Peter Polansky of Thornhill, Ont., joined Raonic on the sidelines after losing his first round match in three sets to Karen Khachanov of Russia 7-6 (3), 7-6 (2), 6-4.

On the women's side, Eugenie Bouchard of Westmount, Que., advanced to the second round of the tournament with a 6-3, 7-6 (5) win over France's Oceane Dodin.

Bouchard will face top-seeded Simona Halep next.