Azarenka ends Wozniacki's hopes

Melbourne - Comeback queen Victoria Azarenka won her battle of the former number ones with Caroline Wozniacki on Thursday to dance her way into the Australian Open third round.

The Belarussian, a two-time Australian champion who is returning from injury, again showed why she is the most dangerous unseeded player at this year's tournament when she upset the eighth seeded Wozniacki from Denmark 6-4, 6-2.

After completing the hard-fought victory in one hour 38 minutes, Azarenka showed off her dance moves to the Melbourne Park crowd, .

"I really tried to stay focused and tried to take my opportunities," said the 25-year-old, who battled injuries and depression in 2014, entering this year's tournament ranked 44 in the world.

"It's really satisfying to be able to play again.

"I just love to dance... I just might as well enjoy myself on the court."

There was little to celebrate for Wozniacki, who slumped to her worst ever performance at Melbourne Park after reaching the semi-finals in 2011. She had never exited before the third round in seven previous campaigns.

On paper, the showdown between two former world number ones was worthy of a place at the business end of a Grand Slam.

In reality, the intensity on display lived up to the billing but it was an error-strewn display from both players in humid conditions, with Azarenka eventually prevailing in a war of attrition.

She will now meet Czech 25th seed Barbora Zahlavova Strycova in the third round an is on course to face top seed Serena Williams in the quarter-finals.

Wozniacki said before the match that Azarenka was one of her best friends on tour, but the Belarussian showed no sentiment as she went after the Dane's serve, dominating with two early breaks.

Azarenka also displayed no sign of the foot injuries that wrecked her 2014 season, repeatedly darting into the net and throwing herself at returns with abandon.

Reeling from the early onslaught, Wozniacki fought back with two breaks of her own as the first set turned into an arm wrestle.

The turning point came in the ninth game, which went to deuce four times before Azarenka claimed yet another break with a forehand down the line, going on the serve out the set after 58 minutes.

Azarenka took an early break in the second and held onto the advantage to seal the victory.

Results from day four of the Australian Open at Melbourne Park on Thursday:

Men's singles

2nd round

Steve Johnson (USA) bt Santiago Giraldo (COL x30) 6-3, 6-4, 6-2
John Isner (USA x19) bt Andreas Haider-Maurer (AUT) 6-4, 7-6, (7/4), 4-6, 6-4
Jarkko Nieminen (FIN) bt Matthias Bachinger (GER) 7-6 (7/4), 7-5, 7-5
Guillermo Garcia-Lopez (ESP) bt Alejandro Gonzalez (COL) 6-1, 6-3, 6-3
Kei Nishikori (JPN x5) bt Ivan Dodig (CRO) 4-6, 7-5, 6-2, 7-6 (7/0)
Feliciano Lopez (ESP x12) bt Adrian Mannarino (FRA) 4-6, 4-6, 7-6 (7/3), 4-0 retired
Novak Djokovic (SRB x1) bt Andrey Kuznetsov (RUS) 6-0, 6-1, 6-4
Stan Wawrinka (SUI x4) bt Marius Copil (ROU) 7-6 (7/4), 7-6 (7/4), 6-3
Gilles Muller (LUX) bt Roberto Bautista Agut (ESP x13) 7-6 (7/5), 1-6, 7-5, 6-1
Vasek Pospisil (CAN) bt Paolo Lorenzi (ITA) 6-7 (3/7), 7-6 (7/4), 6-3, 6-4
Gilles Simon (FRA x18) bt Marcel Granollers (ESP) 7-6 (7/5), 6-2, 6-4
David Ferrer (ESP x9) bt Sergiy Stakhovsky (UKR) 5-7, 6-3, 6-4, 6-2
Jerzy Janowicz (POL) bt Gael Monfils (FRA x17) 6-4, 1-6, 6-7 (3/7), 6-3, 6-3
Fernando Verdasco (ESP x31) bt Go Soeda (JPN) 6-3, 6-2, 7-6 (7/3)

Women's singles

2nd round

Agnieszka Radwanska (POL x6) bt Johanna Larsson (SWE) 6-0, 6-1
Venus Williams (USA x18) bt Lauren Davis (USA) 6-2, 6-3
Timea Bacsinszky (SUI) bt Anna Tatishvili (USA) 6-7 (5/7), 6-3, 6-2
Garbine Muguruza (ESP x24) bt Daniela Hantuchova (SVK) 6-1, 1-6, 6-0
Serena Williams (USA x1) bt Vera Zvonareva (RUS) 7-5, 6-0
Camila Giorgi (ITA) bt Tereza Smitkova (CZE) 6-1, 6-4
Elina Svitolina (UKR x26) bt Nicole Gibbs (USA) 7-6 (7/3), 7-6 (8/6)
Dominika Cibulkova (SVK x11) bt Tsvetlana Pironkova (BUL) 6-2, 6-0
Varvara Lepchenko (USA x30) bt Ajla Tomljanovic (AUS) 6-1, 7-6 (7/1)
Madison Keys (USA) bt Casey Dellacqua (AUS x29) 2-6, 6-1, 6-1
Alize Cornet (FRA x19) bt Denisa Allertova (CZE) 6-4, 6-7 (2/7), 6-2
Madison Brengle (USA) bt Irina Falconi (USA) 6-1, 6-3
Petra Kvitova (CZE x4) bt Mona Barthel (GER) 6-2, 6-4
Barbora Zahlavova Strycova (CZE x25) bt Chang Kai-chen (TPE) 6-1, 7-5
Victoria Azarenka (BLR) bt Caroline Wozniacki (DEN x8) 6-4, 6-2