Melbourne: Japan's Kei Nishikori duelled with Marinko Matosevic over five gruelling sets in baking heat before advancing at the Australian Open on Tuesday. The 16th seed was on court for three hours 41 minutes before subduing the Australian 6-3, 5-7, 6-2, 4-6, 6-2 to reach the second round. (Click here for latest on Australian Open)
With new coach Michael Chang watching in the stands, Nishikori finished the better in the 40 Celsius (104 Fahrenheit) heat to fight off the 54th-ranked Matosevic.
Nishikori, who beat Tomas Berdych in the final of the exhibition Kooyong Classic in Melbourne last weekend, will play Serbian qualifier Dusan Lajovic in the next round.
"I'm happy to win. It was not easy conditions with the heat and the wind," he said. "It's always tough to play the first round. You get tight and anything can happen. But I'm happy to win in fifth set." (Also read: Federer marches into second round)
Former French Open champion Chang is working in an advisory capacity with Nishikori, who is aiming to crack the world top 10.
Asia's most accomplished men's player recorded his best Grand Slam result in Melbourne in 2012, when he reached the last eight, and when he appeared in the Roland Garros fourth round in 2013 he was the first Japanese man in 75 years to progress as far. (Related: Matosevic hits out at coach)
Chang, known for his tenacious baseline defence and two-handed backhand shots, became the youngest-ever man to win a Grand Slam when he triumphed at the 1989 French Open at the age of 17.
Nishikori jumped out to an early lead after breaking Matosevic's opening service and again in the ninth game to take the opening set. But the Australian proved resilient, levelling the match with the second set after a break in the 11th game.
Matosevic ran afoul of the chair umpire in the third set, receiving two time violations and docked a penalty point to hand Nishikori a 5-2 lead. (Stuttering start to Azarenka's campaign)
Matosevic had a running verbal battle with the chair umpire and he lost the third set with a service break to give Nishikori the upper hand.
The Australian kept the pressure on Nishikori and broke him twice on the way to taking the match into a fifth set in the stifling heat. (In pictures: Melbourne on fire)
But Nishikori got an early break to take control of the deciding set as he fought off Matosevic's challenge. The loss extended Matosevic's winless run at Grand Slams to 12 matches stemming back to the 2010 Australian Open.
Matosevic, now coached by former Grand Slam doubles champion Mark Woodforde, is also yet to win a five-set match. Matosevic was also docked a point by the chair umpire for his second time violation at a crucial stage in the third set, allowing Nishikori to claim a 5-2 lead.