Updated

Melbourne, Australia (SportsNetwork.com) - Two-time defending champion Victoria Azarenka and former titlist Maria Sharapova were first-round victors in Tuesday's action at the Australian Open, the first Grand Slam event of the year.

On a sweltering Day 2 at Melbourne Park, the former world No. 1 Azarenka, seeded second, defeated Swede Johanna Larsson 7-6 (7-2), 6-2, while the third-seeded former top-ranked star Sharapova handled American Bethanie Mattek-Sands 6-3, 6-4.

Azarenka, who lost to the great Serena Williams in a final in Sydney two weeks ago, was tested at Rod Laver Arena.

"Yeah it was a tough set first. The match was going to be tricky ... the weather was not helping," Azarenka said. "I had to play a little bit and find my rhythm."

Azarenka hasn't lost at this event since 2011, as she defeated two-time runner-up Li Na in last year's final and Maria Sharapova in the 2012 championship match.

Her second-round opponent on Thursday will be Czech Barbora Zahlavova Strycova, while up next for the career Grand Slam winner Sharapova will be Italian Karin Knapp. Sharapova reached the semifinals the last two years in Melbourne, titled here in 2008, and is a two-time Aussie runner-up.

Meanwhile, fifth-seeded Pole Agnieszka Radwanska had her hands full with Yulia Putintseva of Kazakhstan, but eventually posted a 6-0, 5-7, 6-2 victory, and eighth-seeded former world No. 1 Jelena Jankovic of Serbia whipped Japan's Misaki Doi 6-1, 6-2.

The former Wimbledon runner-up Radwanska's second-round opponent will be Belarusian Olga Govortsova.

Tenth-seeded former top-ranked star Caroline Wozniacki of Denmark drilled Spain's Lourdes Dominguez Lino 6-0, 6-2, while 11th-seeded rising Romanian Simona Halep also had little trouble in a 6-0, 6-1 victory over Poland's Katarzyna Piter, and 13th-seeded American Sloane Stephens erased Kazakhstan's Yaroslava Shvedova 7-6 (7-1), 6-3. Stephens shocked Williams in a quarterfinal bout here a year ago.

Playing her first Grand Slam match since her New Year's Eve engagement to golfer Rory McIlroy, Wozniacki did everything she could to keep cool on Tuesday.

"Every time in the changeovers, ice bags, ice towels, everything; and then in the second set I could feel they were starting to heat up even more," Wozniacki said. "I put the bottle down on the court and it started melting a little bit underneath, the plastic, so you knew it was warm."

Sixteenth seed Carla Suarez Navarro of Spain moved on with a 6-3, 6-2 victory over American Vania King, while Ukrainian Elina Svitolina swept past 19th-seeded two-time major champion Svetlana Kuznetsova of Russia 6-3, 6-3, and 20th-seeded Slovak Dominika Cibulkova subdued former French Open champ Francesca Schiavone 6-3, 6-4.

In other action involving seeds, New Zealand's Marina Erakovic doused No. 21 Romanian Sorana Cirstea 6-4, 7-6 (8-6); Spain's Garbine Muguruza, fresh off her first career WTA title in Hobart last week, took out No. 24 Estonian Kaia Kanepi 6-2, 2-6, 6-2; No. 25 Frenchwoman Alize Cornet was leading Slovenian Polona Hercog 1-0 in the opening set when Hercog retired; No. 29 Russian Anastasia Pavlyuchenkova bested Brazilian Teliana Pereira 7-6 (9-7), 6-4; No. 32 Slovak Magdalena Rybarikova got past former top-10 German Andrea Petkovic 6-2, 6-3; and No. 33 Serb Bojana Jovanovski overcame Slovak Jana Cepelova 6-7 (1-7), 6-1, 6-3.

Several other women reached the second round, including Americans Christina McHale and Varvara Lepchenko, Italian Camila Giorgi, and Japan's Ayumi Morita and Kurumi Nara.

The second round will commence Wednesday, as the current world No. 1 Williams will take on Serb Vesna Dolonc. Williams is a 17-time major singles champ, including an Open Era-record five Aussie Open crowns, with her last one coming in 2010.

In other action involving top-10 seeds, a No. 4 Li will encounter Swiss Belinda Bencic and No. 9 German Angelique Kerber will battle Russian Alla Kudryavtseva.

Also on Day 3, 14th-seeded former world No. 1 Ana Ivanovic will face German Annika Beck and 15th-seeded Wimbledon runner-up Sabine Lisicki of Germany will tangle with Romanian Monica Niculescu.