Italian Jannik Sinner said his carrot-dressed fans give him "extra belief" after he made a winning start to his Australian Open campaign.

The 22-year-old fourth seed was cheered on by the 'Carota Boys' in his 6-4 7-5 6-3 win over the Netherlands' Botic van de Zandschulp at Melbourne Park.

The group dress as carrots after seeing Sinner eat one at a changeover during a match in Vienna in 2019.

"They are getting more famous than I am," Sinner said.

The six fans later gave their own news conference at Melbourne Park, complete with a rendition of "Ole, Ole, Ole, Sinner, Sinner".

"It feels good. I was not expecting them to come here, but it's nice to see them in the stands," Sinner said.

"We have made some great memories together, with all the support they give me.

"Maybe this support gives me in the key moments this extra belief maybe."

No Italian player has reached reach the Australian Open singles final.

Sinner, who led Italy to the Davis Cup title in November, took the first two sets against Van de Zandschulp with a single break of serve.

He found himself behind in the third as world number 59 Van de Zandschulp survived four break points before taking his first for a 2-0 lead.

Sinner responded emphatically, winning six of the following seven games to close out a comfortable victory on the opening day and set up a second-round meeting with Dutch qualifier Jesper de Jong.

"My first match of the season and it means a lot to start off with a win," said Sinner.

"Physically, I feel good in good shape. The first round is never easy so I can be happy with today."