Showman Nick Kyrgios pulled victory "out of a hat" Tuesday in his first match for a year, rallying from a set down to get his Australian Open preparations off to a winning start.

The enigmatic 25-year-old last performed in February 2020 at the Acapulco Open, before a wrist injury and then the coronavirus pandemic brought his season to a halt.

He opted not to travel for the US or French Opens, but said at the weekend he was mentally refreshed and excited to be back.

The Australian took time to get his groove back against 209th-ranked Frenchman Alexandre Muller, losing the first set, then needing left knee treatment before knuckling down to win 3-6, 6-4, 7-6 (7/4) in the Murray River Open.

"It was a tricky one, I haven't played a competitive match in about a year and I dealt with a couple of injuries when in quarantine," he said.

"I was just excited to come out here, any opponent for me was going to be tricky, I just wanted to find my feet. 

"I just somehow pulled it out of a hat, which seems to be the story of my career, so just happy to get through. The body feels ok."

Now ranked 47, he will next play fellow Australian Harry Bourchier.

The Murray River Open is one of two ATP events being run concurrently at Melbourne Park ahead of next week's Australian Open.

Two-time Australian Open quarter-finalist Tennys Sandgren was also in the winners' circle, beating fellow American John-Patrick Smith 6-3, 5-7, 6-4 in the Great Ocean Road Open.

Sandgren saved 11 of the 15 break points he faced to set up a clash next up with Italian Salvatore Caruso.

Seventeen-year-old Spaniard Carlos Alcaraz also advanced when his Hungarian opponent Attila Balazs retired with heel pain, setting up a second-round clash with top seed David Goffin.