Zach O’Brien scored two goals and assisted on another, leading the Newfoundland Growlers to a 5-4 ECHL victory over the Maine Mariners (19-15-0-1) on Wednesday in St. John’s, Newfoundland.

O’Brien’s second goal put the Growlers (23-11-1-0) up 5-2 midway through the third period. Maine (19-15-0-1) got goals from Morgan Adams-Moisan and Jason Salvaggio 1:07 apart to pull within one with 4:33 remaining, but the Mariners managed just two more shots on Newfoundland goalie Brad Barone (21 saves).

Salvaggio finished with two goals for the Mariners, and Hannu Toivonen made 22 saves.

TENNIS

AUSTRALIAN OPEN: Top-ranked Novak Djokovic and Simona Halep, as expected, were given the No. 1 singles seedings.

Defending champion Roger Federer is seeded No. 3 after Rafael Nadal, while women’s defending singles champion Caroline Wozniacki, who beat Halep in last year’s final at Melbourne Park, is No. 3 behind second-seeded and 2016 champion Angelique Kerber.

Serena Williams, who won the Australian Open in 2017 while pregnant with daughter Alexis Olympia, returns as the 16th-seeded player after missing last year’s tournament.

SYDNEY INTERNATIONAL: Ashleigh Barty broke Simona Halep’s serve in the final game to beat the No. 1-ranked Halep 6-4, 6-4 in the second round of the Australian Open leadup event.

It was Halep’s first match since October after a lengthy layoff due to a herniated disc in her back. Halep won last year’s French Open and lost to Caroline Wozniacki in the Australian Open final.

ASB CLASSIC: Top-seeded John Isner fell in the second round at Auckland, New Zealand, losing 7-6 (3), 7-6 (5) to fellow American Taylor Fritz.

On a good day for young Americans, Tennys Sandgren of the United States beat third-seeded Marco Checchinato of Italy 6-3, 6-3.

HOBART INTERNATIONAL: Belinda Bencic eased into the quarterfinals at Hobart, Australia, beating Australian wild card Zoe Hives 6-2, 6-4.

DELRAY BEACH OPEN: Juan Martin del Potro plans to make his season debut at the Florida tournament next month. Del Potro is recovering after fracturing his right kneecap in October.

SOCCER

MLS: Mark Geiger, the first American to referee in the knockout stage of the World Cup, is retiring after 15 seasons in Major League Soccer.

The Professional Referee Organization, which oversees on-field officials in the United States and Canada, said the 44-year-old will become its director of senior match officials and lead coaching education for MLS officials.

HIGH SCHOOLS

GIRLS’ BASKETBALL: Anna DeWolfe scored 26 points and Camille Clement added 16 to lead Greely (9-0) to a 65-28 win over York (3-5) Tuesday in Cumberland. Nina Howe’s seven points led the Wildcats.

BOYS’ HOCKEY: Jake Nelson had four goals and an assist to lead York (5-4) to a 5-2 win against Gorham (5-2) Tuesday in Dover, New Hampshire.