Vettel won the Italian Grand Prix – his eighth of the season – to extend his lead in the drivers’ standings to 112 points, with six races left.
Britain’s Jenson Button pipped Ferrari home favourite Fernando Alonso to second, while McLaren team-mate Lewis Hamilton finished fourth.
It means the German could seal back-to-back championships as soon as two weeks’ time in Singapore, if other results go his way.
“Very emotional,” Vettel described the win, adding: “This circuit means a lot to me and has been very special - my first win was here so when I crossed the line I remembered every single bit.”
Vettel’s Red Bull team-mate Mark Webber, and until yesterday his closest challenger, crashed out early on and then declared the title race all but over.
“I think we’re all battling for second now,” said Webber. “I think Seb needs to have a very, very, incredibly disappointing finish to the season for anyone to take the championship off him at this point. He’s in a great position.”
Alonso, who darted to the front from fourth on the grid before Vettel reasserted his authority on lap five, climbed to second in the standings with his third place.
But he was denied a better result, much to the disappointment of the Ferrari-loving Monza crowd, by Button, who was left to rue a poor start. He had to fight his way back up the pack after slipping from third on the grid to seventh place.
“It was a really fun race, fighting with Lewis, with Michael, and with Fernando. It wasn’t for the lead, which was a shame,” he said. “It is great to get a second but you always want a lot more.”
Hamilton lost valuable time when stuck behind veteran Michael Schumacher, who finished fifth, and could not hide his disappointment at the outcome, having started on the front row of the grid.
“It was not a great result,” said the Englishman. “I started second and I fell back two places. I’m definitely not happy, but that is motor racing.
“I’m happy that I finished and got some points for the team so that’s a good step. I’m okay. We got some points and I finished the race so I can’t complain really.”
ITALIAN GP | RESULTS AND STANDINGS
1. Vettel, Red Bull 1h20:46.172
2. Button, McLaren +9.590
3. Alonso, Ferrari +16.909
4. Hamilton, McLaren +17.471
5. Schumacher, Mercedes +32.677
1. Vettel, Red Bull 284 points
2. Alonso, Ferrari 172
3. Webber, Red Bull 167
4. Button, McLaren 167
5. Hamilton, McLaren 158