Bent fired in a first-half double - the opener coming after just 36 seconds for the fastest goal in the Premier League this season.
But the striker could possibly have had four if he hadn't been denied twice by Spurs keeper Heurelho Gomes from the penalty spot.
Bent did beat the Brazilian from the spot for his second but, when referee Lee Mason awarded to further penalties, the keeper was up to the test, pulling off two great saves to deny his former team-mate.
The Black Cats got off to a rapid start, taking the game to the visitors and winning a corner within seconds of the kick-off.
Fraizer Campbell met the resulting centre with a diving header only to see Gomes push it away.
However, the Spurs keeper only managed to play the ball towards Bent, who fired home clinically.
Tottenham's first real chance of any real merit came on 25 minutes but David Bentley's header was calmly gathered by Sunderland keeper Craig Gordon.
Just before the half-hour mark, Sunderland were two goals to the good. Steed Malbranque cut inside to fire at goal and Gomes saved, but the bouncing ball struck Kyle Walker, who appeared to raise his hand and referee Lee Mason pointed to the spot.
Bent stepped up to confidently drill the ball past Gomes, who guessed the right way but didn't get anything on the strike.
The Black Cats frontman could have had another just before half-time as Campbell went over the trailing leg of Luka Modric in the area and the hosts were awarded their second spot-kick of the afternoon.
Bent stepped up again and again Gomes guessed the right way, but this time he pulled off a great save.
Tottenham boss Harry Redknapp brought on Jermain Defoe and Niko Kranjcar at the restart to try to kick-start his side and it almost had the desired effect.
Defoe raced through on to the ball on 49 minutes but Gordon was quick off the line to make a great stop.
And five minutes later the diminutive striker broke through again but fired wide of the mark.
Sunderland could have had the game killed off on the hour mark. David Meyler chased on to ball over the top and cut into the area before going down under a challenge from Wilson Palacios.
That made penalty number three for the Black Cats and Bent was called to the spot once more.
Gomes again guessed right and pushed the effort on to the post before gathering at the second attempt.
The Wearsiders thought it was game over on 64 minutes as Anton Ferdinand fired past Gomes and into the net, but Mr Mason had already blown for a foul after Campbell had collided with the Spurs keeper.
Spurs stepped things up a gear and forced Sunderland onto the defensive with Gordon pulling off saves from Bentley and substitute Peter Crouch.
But the hosts made sure on 85 minutes as Jordan Henderson's deep cross was met by a bicycle-kick from Bolo Zenden with the ball rocketing into the net to seal the win.