France's Corentin Moutet burnished his credentials with a battling come-from-behind win over American Frances Tiafoe, but his veteran compatriot Richard Gasquet crashed at the first hurdle as the ATP Tour resumed Monday.
NextGen star Moutet, 21, posted a career-best result when he stormed into the final of the Qatar Open as a qualifier last year, finishing runner-up to Russian world number eight Andrey Rublev.
And he started 2021 well, ousting 2019 Australian Open quarter-finalist Tiafoe 3-6, 6-4, 6-4 in the Murray River Open, one of two ATP events being run concurrently at Melbourne Park ahead of next week's Australian Open.
"It was so nice to play a match," Moutet said.
"It was a long time since I've played, especially in front of people. It wasn't an easy one, because I had to play against a tough opponent who is a great player. A tough match, but definitely a lot of pleasure."
But 14th seed Gasquet didn't fare as well, crashing to 194th ranked American Mackenzie McDonald 7-6 (7/2), 7-5.
Fellow American Tommy Paul, the 15th seed, was another winner, motoring past Briton Cameron Norrie in three sets.
Top seeds Stan Wawrinka and Grigor Dimitrov had byes into the second round.
Slovenian 13th seed Aljaz Bedene and big-serving South African Kevin Anderson were among the winners in the Great Ocean Road Classic.
The biggest names in the game, including Novak Djokovic and Rafael Nadal, are playing the ATP Cup teams event, which gets underway in Melbourne on Tuesday.