LONDON (Reuters) -World number one Jannik Sinner eased effortlessly into the second round at Wimbledon, as neither the stifling heat nor fellow Italian Luca Nardi could knock him out of his comfort zone in a 6-4 6-3 6-0 victory on Tuesday.

Returning to the Grand Slam stage for the first time since his epic French Open final defeat by Carlos Alcaraz, the three- times major winner had a much less testing workout against world number 95 Nardi.

His compatriot had spoken in the past about learning from Sinner but this was a lesson in the differences between the best and the rest.

Sinner was bigger, stronger, faster, hit the ball harder and served better, and although Nardi did his best to hang on to his coat tails in the first two sets, his compatriot was simply too good.

"I am very happy to come back here, it's a special place for me and playing against an Italian is very unfortunate for us but one has to go through so I'm happy that it's me," he said as the fans warmly saluted his victory.

Sinner's three Grand Slam successes have come on hardcourts in Australia and the U.S., while he has only once reached the semi-finals at the All England Club.

Yet even against Nardi's limited resistance, he showed he has the tools, the booming serve and walloping flat forehand, to thrive on Wimbledon's lawns.

Sinner's preparation was far from smooth, losing to Alexander Bublik in his second match at Halle in his only grasscourt warmup event and splitting from his trainer and physiotherapist days before the Grand Slam got underway.

Yet having played only two matches since his gruelling Roland Garros final against Alcaraz, he looked fresh as he set about demolishing Nardi.

RELENTLESS PRESSURE

Sinner's pressure was relentless, and Nardi did well to save four break points in the first set before eventually crumbling under an increasingly hostile assault in the 10th game.

A stunning forehand winner brought up another two break points for Sinner and while the first went begging, there was no further reprieve for the 21-year-old.

If anything was going to unsettle Sinner it was the fierce heat on Court One as Wimbledon basked in the second day of a punishing heat wave, but with ice-packed towels draped around his neck at each change-over, the world number one never looked like losing his cool.

He eased through the second set in cruise control after breaking for a 2-0 lead, conceding only a handful of points on serve as Nardi's efforts looked increasingly forlorn.

The motorbike-loving Nardi had no answer as Sinner went full throttle through the final set, breaking in the opening game and twice more before clinching victory with a service winner.

Sinner, who faces Aleksandar Vukic in the next round, may have feared a less than welcoming reception after he served a three-month suspension this year having agreed a settlement with the World Anti-Doping Agency (WADA), but he was cheered throughout by the crowd.

"The atmosphere is amazing actually," he said. "So thank you for coming out."

(Reporting by Toby Davis, editing by Ed Osmond)