Emmanuel Adebayor's second brace in a week secured victory for Tottenham as they came from behind and scored two late goals against battling West Brom.
The hosts took an early lead when Youssouf Mulumbu headed in, but Spurs soon levelled as Adebayor scored on the rebound following his penalty miss.
Jermain Defoe made it 2-1, surging forward and firing in from 22 yards.
Spurs added another on the counter-attack as Gareth Bale set up Adebayor, who scored from 12 yards.
The scoreline flattered Spurs, who were disappointing in the first half and lacked creativity in central areas, with Rafael van der Vaart (hamstring) and Luka Modric (ill) both out.
The visitors improved after half-time, when the score was 1-1, with Adebayor and Defoe linking up particularly well, exchanging passes impressively at speed. Both men deserved their goals in the final 10 minutes.
West Brom were left to rue a series of refereeing decisions from Lee Probert before half-time, as they had a goal claim and a strong penalty appeal rejected - as well as having a spot-kick controversially given against them.
The home side had started confidently and were rewarded in the 10th minute. Steven Reid swung in a lovely cross from the right to pick out Mulumbu and the Baggies midfielder - in space between Younes Kaboul and Ledley King - scored with his free header from seven yards out.
Spurs were back in the game on 25 minutes as Aaron Lennon cut into the penalty area at pace from the right and went to ground, apparently after a touch from Nicky Shorey. Adebayor scored at the second attempt after Ben Foster blocked his weak spot-kick.
West Brom were soon feeling further aggrieved when Jerome Thomas, on the charge, felt he was pushed in the back by Kyle Walker but was awarded no penalty.
And, soon afterwards, Probert denied them a goal for a foul on Brad Friedel, as the keeper appeared to carry the ball over the line when collecting a deflected Reid cross.
Next West Brom were complaining when Sandro - already booked - did not receive a second yellow for a late challenge on Mulumbu. The controversy continued when the Baggies had a second penalty shout rejected as Shane Long went down when tussling with King.
Spurred on by a sense of injustice, West Brom finished the half strongly with Mulumbu's drive forcing Friedel to save.
The out-of-sorts visitors made a better start to the second half as Adebayor forced an excellent save from Foster. Probert then made another big call against West Brom in the 65th minute, when James Morrison went down in the box while battling with Kaboul for the ball.
The game continued in a see-saw fashion until Tottenham finally struck a killer blow on 81 minutes through a devastating counter-attack. Adebayor's backheel close to the halfway line sent Defoe charging forward before he finished with his low shot.
With West Brom committing men forward and still creating openings, Tottenham finally exposed them deep into injury time.
Kaboul's long ball picked out Bale, who cut the ball across for Adebayor. Foster could only help the striker's 12-yard shot on its way into the net, as Spurs exhibited their ruthlessness again.
West Brom manager Roy Hodgson: "We've had more penalties given against us, I think, than any other team.
"I see players go down in our penalty areas after challenges which don't look particularly vicious. Then I see our players go down in the penalty area which don't look vicious.
"The referee makes the decisions about which he thinks are the ones to give and not the ones to give.
"I thought the shape of the team was good, the passing was good, the movement was good and the result was disappointing."
Tottenham manager Harry Redknapp: "We started poorly and didn't move the ball quick enough. They went in front and there was more chance of them going two up at that time than us pegging it back.
"But then, the first time we upped the pace of the game, we got the penalty. In the second half, we opened them up and should have scored a lot more goals.
"We lost Rafael van der Vaart with a hamstring injury but Jermain Defoe has been in fantastic form."