The Italian, who had started from pole but quickly dropped back to sixth, crossed the line 13.7 seconds clear of McLaren’s Oscar Piastri with Ferrari’s Charles Leclerc completing the podium.
Antonelli’s Mercedes teammate George Russell crossed the line fourth with world champion Lando Norris fifth in the other McLaren, ahead of Ferrari’s Lewis Hamilton.
The teenager’s win at Suzuka came on the heels of his victory in China and gave him a nine-point lead over Russell in the overall standings.
It also made him the first Italian to win two F1 races in a row since Alberto Ascari in 1953.
Antonelli inherited the lead when his rivals, including teammate Russell, pitted for fresh tyres shortly before a heavy crash by Haas racer Oliver Bearman triggered a safety car.
That gave Antonelli the chance to pit and keep the lead, leaving Russell, who had stopped just a lap earlier, cursing his luck.
“I was lucky with the safety car but the pace was unbelievable in the end,” said Antonelli on the team radio.
“We definitely dodged a bullet today,” his race engineer responded.
Bearman was given the all-clear by doctors after limping away from the high-speed crash, which came after he closed rapidly on Franco Colapinto’s Alpine and went onto the grass before sliding into the barriers hard.
He was given an X-ray at the circuit’s medical centre which revealed a right knee contusion but no fractures, a Haas spokesperson said.
Norris also pitted under the safety car to move up to third but he was unable to hang on to the podium spot.
Pierre Gasly was seventh for Alpine while Red Bull’s four-times world champion Max Verstappen salvaged some points in eighth.
Liam Lawson was ninth for Racing Bulls with Esteban Ocon 10th in his Haas. (Reuters)
Edited by Edmond Fong
