After Spurs had bossed the first half but hardly troubled West Brom goalkeeper Ben Foster, it took until the 74th minute for the home side to open the scoring via Benoit Assou-Ekotto's deflected strike from range.
Not long before that goal Emmanuel Adebayor had come off the bench to make his second Tottenham debut, but it was West Brom substitute Romelu Lukaku who injected an urgency and attacking impetus into the visitors which culminated in James Morrison's stoppage-time equaliser.
Spurs head coach Andre Villas-Boas's first home game in charge at White Hart Lane came against the side he lost to in his final game as Chelsea manager back in March. The Portuguese coach was again put under pressure by the Baggies as the final whistle was greeted by more than the odd boo from the home crowd, despite the many encouraging signs in Spurs' performance and West Brom's own part in an exciting final quarter of the game.
Despite completing his return to the club on a permanent basis following last season's successful loan spell, striker Emmanuel Adebayor was only named on the Tottenham bench due to Villas-Boas's concerns over the Togolese's match fitness.
Gylfi Sigurdsson joined Adebayor among the substitutes but another summer signing, Jan Vertonghen, made his first start for the club alongside William Gallas in central defence. Michael Dawson was once more left out of the squad completely, with a move away from White Hart Lane seemingly imminent.
Like Spurs, West Brom boss Steve Clarke once again left his club captain out of the starting line-up as Chris Brunt was on the bench, just as he was for the 3-0 win over Liverpool on the opening day.
Spurs completely dominated the first half in every respect. They had 11 shots throughout an opening period in which they had 66 per cent of the possession, but it was not until the 45th minute when Ben Foster was called into action, and even then it was only to gather up Defoe's tame effort.
Gareth Bale and Aaron Lennon were getting plenty of joy from wide positions, but the lack of both personnel and height in the area meant their aerial crosses were largely redundant and their low balls into the box were fired wide.
After the break West Brom were much more efficient in putting pressure on Tottenham's defenders, and while it took time for that pressure to be converted into chances it softened them up for the arrival of Lukaku midway through the half.
However, it was Tottenham who deservedly went ahead with a little more than a quarter of an hour remaining. Assou-Ekotto, who'd earlier had a well-taken free-kick tipped over the bar by Foster, was on hand to strike low as Sigurdsson's corner came all the way out to him. The strike took a significant deflection off Graham Dorrans that left Foster helpless to stop it hitting the back of the net.
Soon after coming on Lukaku forced a quality low save from Brad Friedel, and the Belgian's strength and movement began to unsettle the hitherto unruffled Spurs back line.
The intensity increased inside the home half to the point where an 89th-minute corner caused pandemonium inside the Spurs box, and Assou-Ekotto had to head Gareth McAuley's effort off the line via the crossbar.
Moments later, a clearly rattled Tottenham were finally breached in the first of four added minutes. As the second wave came following another West Brom corner, this time it was William Gallas who headed off the line and Morrison pounced to coolly stroke home a finish which gave Friedel no chance.
At the final whistle a share of the points was fair for the two coaches, who spent three years working together at Chelsea under Jose Mourinho. The delight in the away end and the dissatisfaction around the rest of the ground was the perfect illustration of the differing expectations and fortunes the pair have experienced in their new jobs thus far.