Referee Andre Marriner denied Tottenham two clear penalties before Bale fired home his 26th goal of the season right at the death to give the home side three points.
Sebastian Larsson bundled Bale over in the box, but the 23-year-old was booked for diving, while Carlos Cuellar clearly handled Clint Dempsey's shot but the referee's whistle stayed silent. Tottenham will have to settle for a place in the Europa League again next season, as Arsenal's 1-0 win at Newcastle ensured that they finished in fourth position.
After beating Arsenal here on March 3 Spurs held a seven-point gap over their biggest rivals, but a run of five wins in their remaining nine games allowed Arsenal to finish above their rivals for the 18th consecutive season.
Tottenham started positively amid a booming atmosphere inside White Hart Lane. Emmanuel Adebayor gave John O'Shea the slip to latch on to Kyle Walker's header but Simon Mignolet tipped the Togolese's shot around the post.
Bale charged through on to Tom Huddlestone's through-ball and entered the box but he collided with Larsson, who used both his arms to bring the Welshman down in the box. The home fans held their breath as Marriner put his whistle to his lips, but tension gave way to anger as the referee booked Bale for diving, which enraged the Spurs bench.
Sunderland stirred momentarily, Connor Wickham taking advantage of a mistake by Jan Vertonghen, but Hugo Lloris took the striker's shot on the chin at his near post.
Tottenham raged against Marriner for the second time in the 51st minute when they were denied what appeared to be another blatant penalty. The ball pinged around the Sunderland box and fell to Dempsey, whose shot was blocked by the outstretched arm of Carlos Cuellar. Marriner again paused for a second before waving play on.
The feeling that nothing was going Tottenham's way continued on the hour when Colback saved on the goal line from both Scott Parker and Aaron Lennon in quick succession. Tottenham continued to pepper Sunderland's goal but Mignolet held strong. Vaughan was then dismissed after picking up a second yellow for a late tackle on Lennon.
Bale drew two top-class saves from Mignolet as the clock ticked towards 90 minutes while the Sunderland stopper had to be at his best to stop Huddlestone from powering home a 25-yard strike. Bale finally grabbed the goal with a fantastic 25-yard curler, but it was not enough to ensure Spurs qualified for the Champions League.
Source: PA
Source: PA