No repeat for Coventry but no disgrace either, as Tottenham avoided a repeat of their 1987 FA Cup final defeat against the Midlanders.
The visiting fans cheered on their side from first minute to last, hoping for a repeat of the greatest day in the club's history, when they defeated Spurs at Wembley to lift the FA Cup. But there was never likely to be an upset once Dempsey put Spurs ahead in the 14th minute with an opportunist goal. Gylfi Sigurdsson swung in a free-kick from the right, Bale flicked on, and Dempsey clipped a half-volley past Joe Murphy.
Emmanuel Adebayor was playing on his own up front in place of Jermain Defoe, one of a trio of regulars rested by Andre Villas-Boas, as Spurs showed they were taking the tie seriously. Scott Parker returned for his first start of the season after a long-term injury absence and the England midfielder looked in commanding form.
The ever dangerous Bale scored his 11th goal of the season on 33 minutes.
Dempsey was provider, trying a shot from the edge of the penalty area, and the ball clipped William Edjenguele's legs before looping high for Bale to volley past Murphy from close range.
Four minutes later, the roles were reversed as Bale swung a corner towards the far post and Dempsey powered a header into the far corner. By this stage Coventry had not managed a shot on target, though Brad Friedel had to be sharp to deal with a couple of crosses.
Robins reorganised his side after the break, making them much tighter and restricting Spurs to attacks on the break. Bale put Adebayor through but Edjenguele muscled the Togo striker off the ball, while Dempsey went close to earning first Spurs hat-trick with two efforts in the closing stages.
Substitute Andros Townsend also hit the side netting twice with long-range efforts in the final minutes as Spurs held on to reach the fourth round, and even a consolation goal escaped Coventry when Conor Thomas was ruled offside after putting the ball past Friedel in stoppage-time.
"We gave Spurs too much time and space in the opening period and they are a top-class side," Robins said. "They were magnificent today. Whenever we got the ball, they were quicker than us and they got it back. It was a shame we didn't get a goal to take some heart from."
"It was a professional performance," said Tottenham's assistant manager Steffen Freund. "In the first half it was a different class. We deserved the win. We've won the FA Cup eight times and want to go all the way."