Champion Sinner races into Australian Open second round after Gaston retires

Jannik Sinner’s quest for a third successive Australian Open title began in ominous fashion on Tuesday as he dominated two sets before France’s Hugo Gaston abruptly retired in a letdown for the Rod Laver Arena crowd.

In his first official match since beating Carlos Alcaraz for the ATP Finals crown over two months ago, the Italian world number two stormed to a 6-2 6-1 lead in just over an hour, racking up 19 winners on the court he has ruled for two years.

Gaston took tablets after the first set, showing something was amiss, but there was a rumble of surprise in the terraces when he crossed to Sinner's side after the second set to offer a handshake and apologies.

After consoling the Frenchman as he sobbed under a towel on his chair, Sinner said he could see Gaston was not at his best but was very happy with his own game.

"I've put in many, many long days in the off-season trying to become a better tennis player," he told reporters. "But at the end of the day the most important part is to go on court and to enjoy, no? It's very special to start the season in a night-session match here in a Grand Slam, the packed stadium, just trying to do your best."

Sinner may have hoped for a bit more match practice after his long off-season but barring his first service game, he barely looked like he needed it.

After finding himself 0-40 down, Sinner fired three aces in the next four points to cancel the early threat.

After breaking Gaston in the sixth game, he never looked back.

Though a favourite to claim the title and his fifth Grand Slam crown overall, Sinner was beaten by arch-rival Carlos Alcaraz in the last major final at the US Open, and left Flushing Meadows determined to add variation to his game.

There was some evidence of that as Sinner carved up Gaston with a slew of angled drop shots.

He said he had also been working hard to improve his serve, slowing his action and adjusting his ball toss - but it was still a work in progress.

"At times I still lose it. It's not a shot I feel very safe with. But at the same time we are working on that," he added.

Sinner will next face Australian James Duckworth for a place in the third round.