Despite qualifying sixth for the Turkish Grand Prix, a commanding drive from Hamilton saw him take the chequered flag ahead of Sergio Perez and Vettel to draw level with Michael Schumacher at the top of the all-time standings in style.
Mercedes team-mate Valtteri Bottas needed an eight-point swing to keep the drivers' championship battle alive for at least another round, but a costly spin on the first corner gave Hamilton an opportunity he never looked likely to pass up and the Finn could only finish 14th.
Vettel was once tipped to be the man to get closest to Schumacher's record, having won four consecutive championships from 2010 to 2013, but he was happy to congratulate his old rival on a momentous achievement.
"He drove fantastically well," Vettel told Sky Sports. "In all fairness, it's a good result for us but it's his day if you make history like that. The first thoughts go to him really.
"It's a massive achievement. I'm happy I can witness [it] first-hand."
Red Bull's Max Verstappen, who finished sixth to close the gap to second-placed Bottas in the driver standings to 27 points, said: "It was pretty obvious of course that he was going to win it, but it's incredible. Very strong driver, of course also today, and he's I guess now the greatest driver in Formula 1® in terms of stats.
"A great result for the whole team as well, they have been so dominant. They definitely deserve it."
Renault's Daniel Ricciardo added: "I saw him for the first few laps, and I was like, 'maybe we'll be okay today' – but then he nearly lapped me!
"To finish the season three races before the end with the title in a shortened season, it's domination. What can I say? Another one, seven times, so big congrats to Lewis."
Hamilton, who has 10 race wins to his name in 2020, needs just one more victory to equal his best return for a single season - which he chalked up in 2014, 2018 and 2019.
He could reach the all-time record of 13 in a season achieved by Schumacher in 2004 and Vettel in 2013.
The 35-year-old is just six away from 100 race wins, three short of a century of pole positions, and has recorded 163 podium finishes in his astonishing career.