Second-seeded Maria Sharapova concluded an opening day of matches on Rod Laver Arena with a 6-4, 6-1 win over Croatian player Petra Martic.
Sharapova, who began the season by winning the Brisbane International title, broke Martic's service in the last game of the opening set and then dominated the second. She'll play fellow Russian Alexandra Panova, a qualifier, in the second round.
Last year, Sharapova reached the fourth round at three Grand Slam tournaments - the Australian Open, Wimbledon and U.S. Open - along with winning her fifth career major at the French Open.
A successful title run at Melbourne Park could see Sharapova supplant Serena Williams at No. 1.
In the night's other big match, Australian Nick Kyrgios overcame a dip in confidence, a lot of nerves and a lack of match fitness to down Federico Delbonis and move into the second round.
Kyrgios was bothered by a back injury and copped a point penalty in an eventful clash with Argentina's Delbonis, but prevailed 7-6 (7-2) 3-6 6-3 6-7 (5-7) 6-3 at Margaret Court Arena to end day one of the tournament.
The talented Australian teen, who beat Rafael Nadal and reached the quarter-finals on Wimbledon debut last year, next faces 23rd seed Ivo Karlovic.
Kyrgios took control of the topsy-turvy match in the deciding set with 11 consecutive points that helped rocket him to a lead of 4-1.
The 19-year-old cranked up his serving speed to 210km/h as he powered to victory, but was far more gun shy in the early stages of the match.
"I didn't feel rusty," Kyrgios said.
"I maybe felt pretty nervous ... a lot of expectation.
"I didn't really have much confidence.
"I haven't played a lot of competitive tennis in the past couple months due to injury.
"Obviously I was a bit looser towards the end the match."
Kyrgios, the top-ranked local men's hope in Melbourne at No.53, admitted pre-match he would not be 100 per cent fit due to the back problem that forced him to miss the Hopman Cup.
That was apparent in the opening set, when Kyrgios swapped breaks and needed a medical timeout due to his sore back.
"I'm really pleased I got through. I'm really happy the way I pulled up," he said.
Kyrgios, having gone down 4-1 in the second set after failing to convert two break points, smashed the offending racquet into the court.
The right-hander from Canberra was cautioned over the incident, regained his composure to save four break points and hold serve but lost it again to help Delbonis reach 5-2.
Kyrgios, who was vocal and demonstrative throughout the match, gave up a point penalty for a fiery outburst.
"I don't really like losing, so I guess that's why I did it," he said.
"Obviously a little bit of frustration out there.
"The guy is playing well and obviously you want to win, so that's how the emotions came out."
- AAP/AP
