Milos Raonic made quick work of a dangerous opponent to reach the fourth round of the Australian Open as he beat Viktor Troicki Saturday and then dedicated the win to the victims of a shooting in Canada which left four people dead and at least two injured.

A gunman opened fire at the La Loche Community School in a remote aboriginal community in Saskatchewan, and at a second location.

The 25-year-old from Thornhill, Ont., took an hour and 46 minutes to advance into the second week of the first major of the season, claiming the match 6-2, 6-3, 6-4.

The match created some stress for Raonic as he took to the court after hearing the tragic news that took place Friday.

"It was a difficult day back home," Raonic said. "There was a shooting in a high school in a small town. I give my thoughts to that community, the families, the students and the school affected.

"We wish you all the best. This win was for that community and a speedy recovery. All of Canada and the world is behind you."

The 13th seed's win was in sharp contrast to his previous match, a struggle lasting for three hours over Tommy Robredo.

Raonic defeated Troicki for a fourth time dating to 2012 and has not dropped a set in the series. He finished with 14 aces, 37 winners and conversions on 5-of-12 break point chances.

Troicki committed 24 unforced errors as Raonic competed in his 20th career Grand Slam and sixth Australian appearance.

Raonic is into the last 16 in Melbourne for the fourth time as he produced his third win of the week in straight sets. He played the quarter-finals a year ago.

The 2014 Wimbledon semifinalist swept up the first two sets against Troicki in an hour with a break per set. The Canadian was broken for his only time in the match as Troicki took a 4-3 lead in the third, only to lose it as the Canadian struck back for 5-4.

Raonic caught the sideline with a service winner to set up match point and advanced when Troicki returned long over the baseline.

Raonic will face Stan Wawrinka, who won his 400th tour-level match with a 6-2, 6-3, 7-6 (3) victory over Lukas Rosol.

Nestor advances in men's doubles

Daniel Nestor and Radek Stepanek defeated Lukasz Kubot and Marcin Matkowski 7-6(4), 6-1 in second-round action in a match that had been postponed a day earlier due to rain.

Ivanovic coach taken to hospital

Ana Ivanovic has lost 4-6, 6-4, 6-4 to Madison Keys under difficult circumstances in a third-round match that was suspended for nearly an hour while her coach, Nigel Sears, was taken to hospital early in the second set at Rod Laver Arena.

The match was stopped at 1-0 in the second set when reports said Sears, father of Kim Sears, who is married to Andy Murray, slipped or fell on stairs near the coach's box.

It was not known if Murray was aware of his father-in-law's health issues while winning a match against Joao Sousa at nearby Margaret Court Arena, although he did not wait for the usual TV interview on court after the match. Media reports said he left Melbourne Park immediately after the match.

Ivanovic led 3-0 in the final set before allowing Keys to come back to win the match.

Murray continues perfect record vs. Sousa

Four-time finalist Andy Murray is through to the round of 16 after beating Portugal's Joao Sousa.

The second-seeded Murray converted six of nine breakpoint chances and served 13 aces in the 6-2, 3-6, 6-2, 6-2 victory. He's beaten Sousa all seven times they've played, including at the 2015 and 2013 Australian Opens.

Murray is trying to become the first man to win a Grand Slam after losing in four finals. He lost in the finals in 2010, 2011, 2013 and 2015.

Azarenka works quickly

Victoria Azarenka also cruised into the fourth round with another quick victory, dispatching Japanese qualifier Naomi Osaka 6-1, 6-1 in 56 minutes.

The two-time Australian Open champion, seeded 14th this year, has lost just five games in three matches so far at Melbourne Park.

Azarenka had 24 winners to only four for Osaka, who was making her Grand Slam main draw debut.

Azarenka said after the match, "It wasn't easy for sure, especially when you don't know who you play … She's a little unpredictable and she surprised me with her game."

Early exit for 3rd seed

​Garbine Muguruza has become the latest casualty in the women's draw, beaten by Barbora Strycova 6-3, 6-2 in the day's first match on Rod Laver Arena.

Muguruza misfired frequently on her groundstrokes, finishing with 32 unforced errors, and looked a bit listless throughout the match.

Since reaching last year's Wimbledon final, the Spanish player has lost in the second round of the U.S. Open and now the third round at Melbourne Park.

Strycova has only been past the third round once before in 38 Grand Slam appearances when she reached the quarter-finals of Wimbledon in 2014.

No. 2 Simona Halep, No. 6 Petra Kvitova and No. 8 Venus Williams have also been eliminated from the tournament.

With files from Bill Scott, The Associated Press