MELBOURNE: Andy Murray triumphed in an epic, five-set Australian Open battle which finished in the early hours of Friday in Melbourne after nine-time champion Novak Djokovic defied injury and a drunken heckler to progress to the third round.Murray hit back to defeat home hope and 159th-ranked Thanasi Kokkinakis 4-6, 6-7 (4/7), 7-6 (7/5), 6-3, 7-5 — the match finishing at just after 04:00.At five hours and 45 minutes it was the longest match in Murray’s career.Djokovic, chasing a 10th Australian Open and men’s record-equalling 22nd Grand Slam, defeated 191st-ranked French qualifier Enzo Couacaud 6-1, 6-7 (5/7), 6-2, 6-0.Ons Jabeur was prime among the numerous seeds to crash out on Thursday although most of the carnage occurred in the men’s draw — second seed Casper Ruud, Taylor Fritz, Alexander Zverev and Diego Schwartzman were all sent packing.Former world number one Murray, 35, will play 24th seed Roberto Bautista Agut of Spain in round three after his second successive five-set triumph this week.“It was unbelievable that I managed to do it, to turn it around,” said the three-time Grand Slam champion, who has a metal hip and looked on the verge of retirement four years ago at Melbourne Park.“I don’t know how I managed to get through it.”Murray had stunned Italian 13th seed Matteo Berrettini in his opening match in another five-setter.Despite the drama, serious questions were being asked of the late finish.“It is essential we create better rules in tennis regarding the weather (light and wind) and starting times or cutoff times for matches,” tweeted tennis legend Martina Navratilova.“Murray and Kokkinakis will finish around 4am.