Tennis: Comeback queen Azarenka wins Open grudge match

Two-time Australian Open champion Victoria Azarenka stormed through her grudge match with American Sloane Stephens on Tuesday to reach the second round at Melbourne Park.

Azarenka, ranked just 44 going into the season-opening Grand Slam after an injury-marred 2014, showed why she is regarded as the most dangerous unseeded player at the tournament as she downed Stephens 6-3, 6-2.

The Belarusian, who controversially defeated Stephens in the 2013 semi-final with the help of a lengthy medical timeout, admitted before Tuesday's match she was uncertain about the reception that awaited her.

But all was forgiven with the crowd cheering on a display that was reminiscent of the former world number one's best before a string of injuries left her battling with depression.

Azarenka left no doubt she was chasing her third Grand Slam title at Melbourne Park after triumphing in 2012 and 2013.

"You've got to win seven matches to win a title and this was a great first round for me to really test my game," the 25-year-old said.

"I'm happy with what I did... Sloane's a tricky opponent who has big weapons so I tried to stay aggressive and take every opportunity and control the game. I really had to stay focused and composed."

The service game of both players was rusty in the early exchanges and they exchanged breaks before Azarenka pulled ahead to take the first set in 29 minutes.

Stephens, who has struggled for Grand Slam success since her 2013 final four run, screamed with frustration as Azarenka took control in the second set, hitting pinpoint returns from the baseline and rushing the net with impunity.

The 21-year-old American, ranked 32 in the world, lifted her own game in response, desperately defending her serve in the second game of the set, which went to deuce seven times.

But it was a temporary reprieve and Azarenka broke her opponent at the next opportunity, overwhelming the American after 75 minutes.

Azarenka faces a potentially tricky second-round clash with either eighth seed Caroline Wozniacki of Denmark or American Taylor Townsend.