Exciting Australian teen Bernard Tomic provided the fireworks with a gripping win over Fernando Verdasco as the Australian Open got under way in sweltering heat on Monday. Nineteen-year-old Tomic came from two sets down on Rod Laver Arena to beat the Spanish left-hander 4-6, 6-7 (3/7), 6-4, 6-2, 7-5 in 4hr 11min as Verdasco faltered in the hot afternoon sun. China's Li Na was another early winner as the Roland Garros champion began her quest to reach back-to-back Australian Open finals with a 6-3, 6-1 win over Kazakhstan's Ksenia Pervak, the world number 40. Defending champion Kim Clijsters raced into the second round and third seed Victoria Azarenka maintained her winning start to 2012 with a comprehensive 6-1, 6-0 demolition of Britain's Heather Watson. Tomic won the Kooyong Classic exhibition event last week and despite going two sets down, he did not flinch against the experienced Verdasco and slowly gained the ascendancy in front of his clamouring home fans. In a thrilling final set Verdasco needed his big serving to fight off Tomic before he was broken in the 11th game, allowing the young Aussie to serve out for a courageous win. The epic victory again showcased Tomic's potential after he became the youngest man in 25 years to reach the quarter-finals of last year's Wimbledon before he lost to world number one Novak Djokovic. "If it was someone else, I think they would have thrown in the towel," Tomic said. "I don't know how I found the energy today. I knew I could've beaten him. I knew I had so many chances to win the first and second. "I think that's one of the reasons that made me push to win that third. After the third, I got the confidence." Former US Open champion Juan Martin del Potro also needed to dig deep before seeing off a gritty challenge from French world number 91 Adrian Mannarino 2-6, 6-1, 7-5, 6-4 over three hours. The 11th-ranked Argentine, whose match was briefly interrupted when a fan collapsed in the sun-baked stands, said he hoped to maintain his pursuit of the game's elite as he continues his recovery from an injury-ravaged 2010."I have the same goal. The first one is play healthy all the year and then if I am still improving my game, I hope to be closer to the top players," he said. "It's a big tournament here to see where my game is, and hopefully I'll be ready for the next round and keep playing well." Elsewhere, former world number three Nikolay Davydenko, a first-round loser to Flavio Cipolla, weighed in on Roger Federer following Rafael Nadal's surprise broadside against the 16-time grand slam champion. The Russian backed comments from world number two Nadal, who complained that Federer, president of the ATP Player Council, was not pushing hard enough for improvements in areas such as pay and scheduling. "I don't know why Roger doesn't support players. I don't know why. Because he doesn't do any problems. He's a nice guy," Davydenko said. "He's from Switzerland. He's perfect. He don't want to do anything. He just tried to be outside from this one," added the Russian. In the women's draw, Clijsters was tested in her opening set against Portuguese qualifier Maria Joao Koehler before racing away with the second to win 7-5, 6-1.