Andy Murray showed no signs of trouble with his sore ankle as he advanced to the Round of 16 at the Australian Open for the ninth straight year, avoiding any chance of an upset against Sam Querrey.

Five-time runner-up Murray served out for a 6-4, 6-2, 6-4 win Friday over Querrey, who has had recent form against the No. 1-ranked player in the third round of a major.

It was Querrey who ended Novak Djokovic's impressive Grand Slam run in the third round at Wimbledon last year. At that time, Djokovic had won four straight major titles — Wimbledon and U.S. Open in 2015 and Australian Open and French Open in 2016.

Murray, who replaced Djokovic in the No. 1 ranking last November, said he was surprised at the six-time Australian Open champion's second-round loss to Denis Istomin.

But he didn't think it changed anything for him unless he reached the final.

"I wasn't scheduled to play Novak today, so my job's to concentrate on Sam and to go into that match with a clear head and a good game plan and try to play well," said Murray, who lost to Djokovic in four of the five finals he has played at Melbourne Park. "I did that.

"Obviously, if you're to get to the final, then it has an effect."

Murray injured his right ankle in the second round, and said he was hesitant at first but warmed into the match against Querrey, who was at the top of his game in the first set.

"I felt better and better as the match went on in terms of my movement," Murray said. "I was moving well at the end — it was very positive."

Murray next plays Mischa Zverev, who had a 6-1, 4-6, 6-3, 6-0 win over Malek Jaziri, and, if results go with the seedings, could have a quarterfinal against Kei Nishikori. The fifth-seeded Nishikori beat Lukas Lacko 6-4, 6-4, 6-4.

Seven-time major winner Venus Williams routed Duan Yingying 6-1, 6-0 in less than an hour to progress to the fourth round for the 10th time since her Australian Open debut in 1998.

"It's good (but) it's never enough," she said, looking ahead to her fourth-round match against Mona Barthel, who beat local hope Ashleigh Barty in three sets. "I've tasted it before and it's always a great feeling because it means, hey, I have an opportunity for the quarterfinals. That's what I'm going to go for."

The last two Americans in the men's draw lost within an hour of each other. After Querrey's exit, No. 23-seeded Jack Sock lost 7-6 (4), 7-5, 6-7 (8), 6-3 to No. 12 Jo-Wilfried Tsonga.

There are no more Australians in the men's draw, either, after Daniel Evans beat Bernard Tomic 7-5, 7-6 (2), 7-6 (3) to go beyond the third round for the first time at a major.

U.S. Open champion Stan Wawrinka was twice broken while serving for the match before finishing off a 3-6, 6-2, 6-2, 7-6 (7) win over Viktor Troicki.

Wawrinka, the 2014 Australian Open winner, will next play Andreas Seppi, who beat Steve Darcis 4-6, 6-4, 7-6 (1), 7-6 (2).

Angelique Kerber had a straight-sets win for the first time in her first Australian Open title defense, 6-0, 6-4 against Kristyna Pliskova. Top-ranked Kerber beat the other Pliskova twin, Karolina, in the last U.S. Open final.

Kerber will next play 35th-ranked CoCo Vandeweghe, who reached the fourth round in Australia for the first time with a 6-4, 3-6, 7-5 win over 2014 semifinalist Eugenie Bouchard.

Two-time major winner Svetlana Kuznetsova was broken twice while serving for the match before finally finishing off former No. 1-ranked Jelena Jankovic 6-4, 5-7, 9-7 in 3 ½ hours. She next plays No. 24 Anastasia Pavlyuchenkova, who beat No. 11 Elina Svitolina 7-5, 4-6, 6-3.

Australian Open organizers were briefed by Victoria state police over an incident in downtown Melbourne where a man deliberately drove into a street crowded with pedestrians, killing three people and injuring 20. Police said the incident, about three kilometers (two miles) from Melbourne Park, had no links to terrorism.

"Be assured there is no threat to the precinct," Australian Open organizers said in a statement.