$ 0 0 Three-time defending champion Novak Djokovic beat Argentina's Leonardo Mayer 6-0, 6-4, 6-4 to cruise into the third round with his 23rd straight win at the AustralianOpen Wednesday. The Serbian second seed, unbeaten at Melbourne Park since 2010, had few problems with the intense heat and was on court for just one hour and 47 minutes. He is bidding to become only the second man after Australia's Roy Emerson to win four consecutive AustralianOpens and his fifth overall in Melbourne. It was an improved performance by Djokovic after his sloppy first-round performance against Slovakia's Lukas Lacko on Monday. He broke the tall Mayer's service five times and did not face a break point on his own serve. He also hit 30 winners to just 11 unforced errors while Mayer made 39 errors. Djokovic, who has had problems in the past with the Melbourne heat, said he was now better prepared for his matches in the Australian summer.