adminStevenage took a shock fourth-minute lead when Joel Byrom scored from the spot, while Spurs lost Michael Dawson to a serious-looking knee injury.
Defoe fired in a well-taken equaliser before Gareth Bale was awarded a controversial penalty.
Emmanuel Adebayor converted from the spot and Defoe’s clinical finish saw Spurs into the quarter-finals.
Tottenham’s recent defeats to Arsenal and Manchester United had threatened to derail what has been another impressive campaign under Harry Redknapp.
And White Hart Lane was stunned into silence when Ryan Nelsen tripped Byrom, who had made a driving run into the penalty area, and the midfielder sent Carlo Cudicini the wrong way in finding the bottom left-hand corner.
Tottenham’s early misery was compounded when Dawson was carried off on a stretcher in the sixth minute, having fallen awkwardly on his knee. Early indications suggested he could be set for another lengthy lay-off.
Just as they had last month at the Lamex Stadium, Stevenage stifled Tottenham’s creative threat and it almost got worse for Spurs when centre-back Jon Ashton rose high to head Lawrie Wilson’s free-kick just wide.
A second goal would not have flattered Stevenage, who were the better side until that point, but Defoe restored parity moments later.
Collecting Bale’s pinpoint long pass with a sublime first touch, he shot past Chris Day to remind Redknapp of his predatory instincts.
Spurs were dealt another injury blow when Aaron Lennon limped off, but of greater concern was the quality of the crosses provided by Stevenage full-backs Wilson and Scott Laird.
Mark Roberts, having poked a shot straight at Cudicini from point-blank range early in the second half, was at the centre of the game’s turning point moments later.
He conceded the second penalty of the evening for a challenge on Bale, although replays showed little contact. Adebayor, a first-half substitute for Lennon, nonchalantly sent Day the wrong way from 12 yards.
Mark Roberts headed against the underside of the bar as Stevenage, benefiting from the impetus provided by substitutes Craig Reid and Jennison Myrie-Williams, went in search of an equaliser.
But Spurs rode their luck and finished off the plucky League One side after good work from Bale.
Latching on to the winger’s quickly taken long throw, Defoe cut inside on to his favoured right foot to lash a low effort past Day — and set up a quarter-final date with Bolton on Saturday, 17 March. — BBC.
Bongani Ndlovu
Online Reporter