MELBOURNE, Australia — When Andy Murray tumbled to the court, clutching his right ankle, the top of the men’s draw at the Australian Open momentarily took on a new complexion.

Top-ranked Murray, a five-time runner-up at Melbourne Park, was leading his second-round match comfortably today when his right shoe caught on the surface in the third game of the third set, and he rolled awkwardly on the ground.

He continued and won that game, talking to himself, saying “It’s not good news.” He saw a trainer during the next change of ends, but decided he didn’t need any extra treatment on his already heavily strapped foot.

Murray went on to win 6-3, 6-0, 6-2 against No. 156-ranked Andrey Rublev, later saying “It’s a little bit sore — not too serious.” “I was moving OK toward the end, so that’s positive,” he said.

It was Murray’s 178th win in a Grand Slam match, joining Stefan Edberg at equal eighth on the list of match winners in the Open era. The 19-year-old Rublev’s first-round win here was his first in a major tournament.

Murray next faces No. 31 Sam Querrey, who had 7-6 (5), 6-0, 6-1 win over 17-year-old wild card Alex De Minaur.

Roger Federer’s progress was more straight forward, beating 20-year-old qualifier Noah Rubin 7-5, 6-3, 7-6 (3) to maintain his record of never failing to reach the third round at the 18 Australian Opens he’s contested.

After back-to-back wins over qualifiers, the degree of difficulty in the 17-time Grand Slam winner’s comeback from a six-month injury layoff will increase. Next up, Federer faces 2010 Wimbledon finalist Tomas Berdych, who had a 6-3, 7-6 (6), 6-2 win over Ryan Harrison.

Also looming, potentially, is No. 5 Kei Nishikori, the 2014 U.S. Open finalist, who set up a third-round match against Lukas Lacko with a 6-3, 6-4, 6-3 win over Jeremy Chardy.

They’re all in the same quarter of the draw as Murray.