Britain's Andy Murray marked his return to the Australian Open - where in 2019 he thought he might have to retire - with a tense five-set win over Georgian 21st seed Nikoloz Basilashvili.
Murray cruised to the first set in 23 minutes but any hopes of a routine win disappeared as Basilashvili recovered.
Momentum swung both ways before Murray, 34, won 6-1 3-6 6-4 6-7 (5-7) 6-4.
The former world number one is the second Briton through to round two after Heather Watson also won.
Emma Raducanu, Dan Evans and Liam Broady play later on Tuesday.