Jannik Sinner launches his bid to win a third Australian Open in a row on Tuesday as Madison Keys also kickstarts her title defence in Melbourne. Two-time former champion Naomi Osaka is also in action on day three of the first Grand Slam of the year, as is highly promising Brazilian teenager Joao Fonseca. Sinner was a comfortable winner over Alexander Zverev in last year’s final and if he wins the tournament again would join Novak Djokovic as the only men in the Open era to win three successive Melbourne crowns.

The Italian second seed faces French world number 93 Hugo Gaston at Rod Laver Arena in the first match of the night session.

The chief threat to his Australian Open dominance is top-ranked Carlos Alcaraz, who is bidding to win the tournament for the first time and seal a career Grand Slam of all four majors at just 22.

The Spaniard eased through his opening match on Sunday in straight sets.

Following defeat to great rival Alcaraz in the US Open final, the 24-year-old Sinner vowed to add more variation to his game.

“We worked a lot on trying to make the transition to the net. The serve we changed a couple of things,” he said.

“When you are at the top level, these are the small details that make the difference.”