Mercedes' Kimi Antonelli . Photo: Reuters
The 19-year-old 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 teammate George Russell crossed the line fourth with world champion Lando Norris fifth in the other McLaren ahead of Ferrari's Lewis Hamilton.
Antonelli's Suzuka win gave him a nine-point lead over Russell in the overall standings.
Haas driver Oliver Bearman was given the all-clear by doctors after limping away from a high-speed crash.
