Defending champion Kim Clijsters and world number one Caroline Wozniacki stormed into round two of the Australian Open Monday as the women\'s favourites showed early form. Third seed Victoria Azarenka and China\'s Li Na, the French Open champion and last year\'s runner-up, also both passed their first tests on a day of searing heat at Melbourne Park. Clijsters saw off Portugese qualifier Maria Joao Koehler 7-5, 6-1, soon after Li won a tough first round match against Ksenia Pervak of Kazakhstan 6-3, 6-1. And on a day when all the big guns came out firing, third seeded Belarusian Victoria Azarenka demolished Britain\'s Heather Watson 6-1, 6-0, and 2010 French Open champion Francesca Schiavone crushed Spaniard Laura Pous-Tio 6-1, 6-3. In the last match on centre court, Wozniacki withstood an early barrage from Rodionova before turning the screws and cruising to victory 6-2, 6-1. The top seeded Dane was at her counter-punching best, absorbing an early blitz of winners from Rodionova and preying on any mistakes to demoralise her opponent. Wozniacki has been criticised for not having any \'killer\' shots, but her superb court movement and ability to get balls back into play were more than enough to defeat Rodionova, who grew ragged as the match went on. Earlier Clijsters, who plans to retire this year, said recent injury problems were behind her as she returned to the scene of her 2011 triumph. Clijsters, who pulled out of this month\'s Brisbane International with a hip problem, was forced to work hard in the early stages by the unknown Koehler, who was playing her first ever main tour match outside Portugal. But, when serving at 5-6, Koehler\'s inexperience told and Clijsters attacked, quickly racing to 0-40, then wrapping up the first set courtesy of a double-fault. Clijsters seized control and broke twice more in the second set to cruise to a comfortable win, keeping her on track for a potential fourth-round clash with Li. \"I\'m feeling good and I\'m happy to say that (the injury) is all behind me,\" the 28-year-old world number 14 said. Like Clijsters, Li was also made to work hard in the first set before taking control in the second, later admitting she had suffered in the hot conditions.  \"I was feeling at the end of the first set really the heat on the court,\" Li said. \"Also I was feeling no air. I couldn\'t breathe. Like I was feeling like, what\'s going on?\" In the first match on Rod Laver Arena, Azarenka dominated Watson as she pressed her claims for a maiden grand slam win. The Belarusian, who won last week\'s Sydney International and is unbeaten in 2012, needed just 67 minutes to overwhelm Watson and move into a second round clash against Australia\'s Casey Dellacqua. \"I think it was a good performance,\" Azarenka said. \"There are a few things for me that I have to work on tomorrow to be better in my second round, but you know, I take what I get. I cannot complain.\" The highest profile casualty on day one was 19th seed Flavia Pennetta, who fell to Russian qualifier Nina Bratchikova 6-3, 1-6, 6-2. Pennetta injured her back in the season-opening tournament in Auckland and subsequently withdrew from Sydney last week. She battled hard but eventually succumbed in one-and-a-half hours. In other matches, eighth seed Agnieszka Radwanska came from a set down to beat colourful American Bethanie Mattek-Sands 6-7 (10/12), 6-4, 6-2 in a match lasting three hours exactly. Slovakian Daniela Hantuchova, the 20th seed, defeated US qualifier Varvara Lepchenko 4-6, 6-3, 6-2, while 16th seed Peng Shuai ensured a good day for the Chinese with a 6-3, 6-4 win over France\'s Aravane Rezai.