Novak Djokovic will look to extend his sensational run of form at the Australian Open on Monday as expectations soar about what he could achieve this year.
All eyes are on the Serbian world number one and his bid for a calendar-year Grand Slam after he fell just short during his brilliant 2015 season.
The 28-year-old is yet to drop a set this year and his performance in the Qatar Open final was described as "perfect" by his flummoxed opponent, Rafael Nadal.
Djokovic could even pick up the first ever men's 'Golden Slam' if he manages to unite the four major titles and be crowned Olympic champion at Rio de Janeiro in August.
He opens his Grand Slam season against South Korea's Chung Hyeon on Monday and is already having to play down his chances of what could be a historic year.
"It's only the beginning of the season. It's too early to talk about what I can or can't do later in the season. I'm here to focus on Australian Open," he told reporters in Melbourne.
"If I am able to do the same or better, like 2015, I'm not sure," he added. "Honestly, as I said, it's just the beginning. I try to take one tournament at a time."
Roger Federer is also in action on day one, against Georgia's Nikoloz Basilashvili, with Djokovic's other main challengers Andy Murray and Stanislas Wawrinka starting on Tuesday.
Djokovic, who has five Australian Open titles, has only lost once in the last five years at Melbourne Park, when he was stopped by Wawrinka in the 2014 quarter-finals.
- Heat illness -
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One wildcard for the Serb could be Melbourne's intense heat, with temperatures forecast at 37 degrees Celsius (98.6 degrees Fahrenheit) on Monday.
Djokovic retired with "heat illness" during his 2009 Australian Open quarter-final against Andy Roddick, but he has steeled himself physically and outlasted Nadal in the 2012 final which ran for nearly six hours.
"Again, you're not the only one on the court. There's an
opponent across the net. He is, of course, handling it as tough as you are handling it. You got to keep that in your mind and try to be tough.
"Whatever is coming our way tomorrow, I'll try to be ready for it."
Murray also has an enviable record at Melbourne Park, reaching four finals in the past six years -- although he is yet to lift the trophy.
His title bid could be distracted by the imminent birth of his first child, which he is desperate to attend even if it means missing the final.
"For me, my child is more important to me, and my wife is more important to me, than a tennis match," said the British second seed.
Federer, as the third seed, could face Djokovic in the semi-finals as the 17-time Grand Slam champion looks to win his first major title since Wimbledon 2012.
The Swiss has won four Australian Opens, but lost to Djokovic in last year's Wimbledon and US Open finals. At 34, he is running out of time to add to his record haul of majors.
A second Australian Open title for Nadal appears a stretch after his slump in 2015, but Wawrinka, champion in 2014, should be a contender after he beat Djokovic in last year's French Open final.
"It's a new year. Hopefully I can do something good this year," said the Swiss.
Outside the top five, Japan's world number seven Kei Nishikori will be looking to get past the quarters for the first time in Melbourne.
Home interest will focus on the farewell of former world number one Lleyton Hewitt, who is playing his final tournament, and the talented but wayward duo of Bernard Tomic and Nick Kyrgios.
