The home side struggled to reach the peak of its powers and was frustrated for the most part by Roy Hodgson's visitors but the striker's second-half effort sealed the points
Spurs dominated the match from start to finish but lacked their usual speed and incisive edge in the final third of the pitch against a defensively resilient West Brom side.
Defoe was the difference, however, as Spurs' fox in the box was able to poach the goal that sealed three points.
Spurs reverted to a 4-4-2 formation in the absence of Scott Parker, who was ruled out with a calf injury. Sandro and Luka Modric were paired in the middle of the park with Defoe joining Emmanuel Adebayor up front.
Eighteen-year-old George Thorne started in midfield for West Brom, with James Morrison only featuring among the substitutes. Chris Brunt and Shane Long missed out due to injury, with Simon Cox starting on the right wing and Graeme Dorrans supporting Peter Odemwingie in attack.
Odemwingie cut an isolated figure from the get-go as the lone striker, finding himself surrounded by the home side’s defensive trio of Sandro, Younes Kaboul and William Gallas. West Brom’s defensive approach did see it through the first 20 minutes without cause for concern, however, as after an early flurry of corners Spurs lacked the tempo required to unsettle Hodgson’s back four and midfield five.
Untroubled in his own half, Kaboul powered into opposition territory unchallenged in an attempt to spark the Spurs attack into life and slipped Gareth Bale into space on the left-hand side. The Welshman fizzed a low cross into the path of Rafael Van der Vaart but his first-time effort was tipped over the bar by Ben Foster.
After both teams had made substitutions forced by injury – Gonzalo Jara replaced Jerome Thomas for West Brom before Jake Livermore was introduced in place of Sandro, who seemed to pull a muscle, for Spurs – Bale and Adebayor linked up well on the edge of the penalty area but the Togolese couldn’t control the final pass, allowing Foster to collect.
Brad Friedel remained untested in the Tottenham goal but Hodgson will have been relatively satisfied with an efficient first-half performance in which the home side was well-contained.
Spurs began to work the ball into the West Brom penalty area more menacingly in the early stages of the second half. After volleying over the bar when a clever Adebayor back heel took him by surprise, Defoe showcased his predatory instinct by moving inside his defender in order to divert Van der Vaart’s cross towards goal but the England forward’s effort just evaded the far post.
There was a sense that frustration was beginning to creep in among the Spurs players and supporters, but after Adebayor ended a promising counterattack with a poor pass his strike partner extinguished the fears of the White Hart Lane faithful.
Defoe’s first touch on a firm Van der Vaart pass into the box popped the ball up into the air but, surrounded by defenders, he neatly brought it under control before swivelling and superbly guiding a placed finish beyond Foster.
Harry Redknapp lost another man to injury as Gallas was forced off, with Sebastian Bassong coming on at center -back, but Spurs continued to control proceedings. Bale stung Foster’s palms with a curled effort from 20 yards which the goalkeeper comfortably held.
The introduction of James Morrison, however, seemed to energize West Brom somewhat, and they carved out their first half-chance when the Scot combined with Odemwingie on the left, but his dangerous cut-back crossed the penalty area untouched.
Sensing Spurs were beginning to take their foot off the pedal, Hodgson introduced another attacking player in the form of Somen Tchoyi. Sure enough, it was the Cameroon forward who tested Friedel with a 25-yard drive after substitute Niko Kranjcar had coughed up possession with a loose pass in midfield.
The home side never looked in too much danger of being pegged back, though, and held on to claim a win that takes it to within three points of second place Manchester United.