Four-time defending champion Novak Djokovic and David Ferrer battled through intense heat to reach the third round of the Australian Open on Wednesday. Second-seeded Djokovic stepped up from his mixed first-round performance to ease past Argentina's Leonardo Mayer 6-0, 6-4, 6-4 for his 23rd straight win at the Open. Third seed Ferrer, who lost in last year's semi-final to Djokovic, needed just over three hours to overcome Frenchman Adrian Mannarino, winning 7-6 (7-2), 5-7, 6-0, 6-3 on Hisense Arena. I physically got stronger - mentally also. All of this plays an important role when you are playing in such conditions Novak Djokovic Djokovic may have retired with heat distress in Melbourne four years ago against Andy Roddick, but he handled Wednesday's 40-degree-Celsius temperatures without difficulty. "As the years go by, I'm more matured as a player, I've learned new things in life," he said. "I physically got stronger - mentally also. All of this plays an important role when you are playing in such conditions. "Generally it's much more efficient for me nowadays to recover and to get ready for the next point than it used to be in 2009 when I retired in my match against Roddick." Djokovic, unconquered at Melbourne Park since 2010, broke Mayer's service five times and did not face a break point on his own serve in his one hour 47 minutes on court. Djokovic's next opponent will be Uzbekistan's Denis Istomin. Spain's Ferrer had a tougher workout against the 71st-ranked Mannarino, losing the second set and having his serve broken five times. Czech seventh seed Tomas Berdych accounted for Frenchman Kenny De Schepper 6-4, 6-1, 6-3 and French ninth seed Richard Gasquet eliminated Russian Nicolay Davydenko in three sets.