Andre Villas-Boas was denied his first win as Tottenham boss as James Morrison snatched a late equaliser for West Brom at White Hart Lane.
Benoit Assou-Ekotto's deflected 25-yard shot looked to have given Spurs victory with 15 minutes of the game remaining.
But the Baggies refused to give in and were rewarded when Morrison stroked home from 10 yards in the last minute.
Draw difficult to take - Villas-Boas
It was a painful end to a frustrating afternoon for Spurs, who created more chances but were wasteful.
However, Steve Clarke's side will rightly point to their growing influence on the game as evidence of this being a very deserved point.
Villas-Boas can be forgiven for being sick of the sight of West Brom, who have played a significant - and largely antagonistic - role in the story of his time in England.
While the Portuguese's first win as Chelsea boss came over the Baggies, it was a defeat by Albion just over six months later that proved to be the last act of his Stamford Bridge 'project'.
Tottenham v West Brom facts
West Brom have won just three of 34 trips to London in the Premier League
Andre Villas-Boas has picked up only three wins from his last 14 Premier League matches
West Brom have kept just one clean sheet in their last 18 Premier League away games
All four of Benoit Assou-Ekotto's Premier League goals have been at White Hart Lane
Six of James Morrison's last seven Premier League goals have been scored away from home
Once again the Midlands club have thrown a spanner in the works to leave the 34-year-old with just three wins from his last 14 Premier League games.
However, there were many positives that Villas-Boas and the Spurs fans - some of whom remain doubtful of his appointment - can take away from this first home game of the season.
They fashioned the greater number of chances, their most potent attacking weapon, Gareth Bale, looks sharp and in Jan Vertonghen they have a centre-back who can grow into an authoritative presence in this division.
Within the first 15 minutes Bale had swung over two dangerous crosses - narrowly missed by team-mates - and sliced a shot wide of goal. He also provided a superb pull-back for Belgian Vertonghen to also fire wide.
This was all encouraging but what the home side needed was a goal and the longer they went without one, the more the crowd's nerves grew and West Brom increased as a presence in the match.
Clarke praises West Brom character
On the evidence of the first two games of this campaign, Steve Clarke - an old colleague of Villas-Boas under Jose Mourinho at Chelsea - is building superbly on the fine work done by predecessor Roy Hodgson at the Hawthorns.
Buoyed by their resilience to all that Spurs threw at them and by the introduction of Romelu Lukaku from the bench, the Baggies burst into attacking life and forced Brad Friedel into two superb saves - one from the on-loan Chelsea striker's angled shot and then from Marc-Antoine Fortune as he bundled into the box.
It was just after this that Tottenham scored, as Assou-Ekotto's long-range drive deflected off Graham Dorrans' head to beat Ben Foster and seemingly give Spurs the win.
However, such is the Baggies' spirit that they kept on attacking and, after hitting the bar during one mad scramble in the box, they capitalised during another, with Morrison finding space in the box to side-foot into the net after the ball had fallen invitingly at his feet. It was too late for Tottenham to respond.
So Clarke's West Brom tenure remains bathed in optimism, while Villas-Boas will be glad that it is another six months before he has to face the Baggies again.
Full Time The final whistle is blown by the referee.
The official flags William Gallas offside. Ben Foster restarts play with the free kick.
Free kick awarded for a foul by Claudio Yacob on Jan Vertonghen. Direct free kick taken by Benoit Assou-Ekotto.
Romelu Lukaku takes a shot. Blocked by William Gallas.
The assist for the goal came from Gareth McAuley.
90:00 +0:21 Goal scored
Goal! - James Morrison - Tottenham 1 - 1 West Brom James Morrison finds the back of the net with a goal from close range to the bottom right corner of the goal. Tottenham 1-1 West Brom.
Corner taken by Chris Brunt, clearance by William Gallas.
Inswinging corner taken right-footed by James Morrison from the left by-line to the near post, Gareth McAuley takes a shot.
Gylfi Sigurdsson takes the outswinging corner, Gareth McAuley makes a clearance.
Gareth Bale takes a shot. Save by Ben Foster. Inswinging corner taken from the right by-line by Gylfi Sigurdsson, Gareth McAuley manages to make a clearance.
The ball is sent over by Gareth Bale, Gareth McAuley manages to make a clearance.
The ball is delivered by Kyle Walker, clearance by Gareth McAuley.
Gylfi Sigurdsson takes a inswinging corner.
Direct free kick taken by Jan Vertonghen.
Booking The referee shows Steven Reid a yellow card.
Steven Reid concedes a free kick for a foul on Gareth Bale.
Foul by Romelu Lukaku on Jan Vertonghen, free kick awarded. Free kick taken by Jan Vertonghen.
Markus Rosenberg is caught offside. Indirect free kick taken by Jan Vertonghen.
Substitution Markus Rosenberg replaces Marc-Antoine Fortune.
Corner from right by-line taken by Chris Brunt.
Assist on the goal came from Gylfi Sigurdsson.
Substitution Jermaine Jenas joins the action as a substitute, replacing Jermain Defoe.
Substitution Chris Brunt comes on in place of Graham Dorrans.
73:30 Goal scored
Goal! - Benoit Assou-Ekotto - Tottenham 1 - 0 West Brom Benoit Assou-Ekotto fires in a goal from long distance to the bottom right corner of the goal. Tottenham 1-0 West Brom.
Corner taken by Gylfi Sigurdsson, Gareth McAuley manages to make a clearance.
Substitution Raniere Sandro goes off and Gylfi Sigurdsson comes on.
Gareth Bale takes a shot. Ben Foster makes a save.
Marc-Antoine Fortune produces a cross, clearance made by Jan Vertonghen.
Marc-Antoine Fortune takes a shot. Save made by Brad Friedel.
Jermain Defoe takes a shot. Save by Ben Foster.
Marc-Antoine Fortune crosses the ball, blocked by Benoit Assou-Ekotto. Outswinging corner taken by James Morrison, Emmanuel Adebayor makes a clearance.
Romelu Lukaku takes a shot. Save by Brad Friedel. Outswinging corner taken from the right by-line by James Morrison, Emmanuel Adebayor makes a clearance.
The assistant referee signals for offside against Jermain Defoe. Ben Foster restarts play with the free kick.
Kyle Walker crosses the ball, clearance made by Gareth McAuley.
Substitution Romelu Lukaku comes on in place of Shane Long.
Substitution Emmanuel Adebayor joins the action as a substitute, replacing Rafael Van der Vaart.
Jermain Defoe takes a shot. Save made by Ben Foster.
Shot by Marc-Antoine Fortune from outside the box goes high over the crossbar.
Benoit Assou-Ekotto challenges Marc-Antoine Fortune unfairly and gives away a free kick. The ball is swung over by Steven Reid, Shane Long produces a header from the edge of the box and misses to the left of the target.
Jermain Defoe has an effort at goal from outside the area missing to the wide left of the goal.
Graham Dorrans takes a shot. Brad Friedel makes a save. Foul by Jermain Defoe on Gareth McAuley, free kick awarded. Direct free kick taken by Gareth McAuley. James Morrison takes a shot from a long way out which goes wide of the right-hand upright.
The ball is swung over by Graham Dorrans, clearance made by Jake Livermore.
Jermain Defoe fouled by Gareth McAuley, the ref awards a free kick. Strike on goal comes in from Benoit Assou-Ekotto from the free kick, save by Ben Foster. Corner taken by Rafael Van der Vaart from the right by-line to the near post, save by Ben Foster.
Shot from deep inside the area by Gareth Bale clears the crossbar.
The referee blows for offside against Shane Long. Benoit Assou-Ekotto takes the free kick.
The ball is sent over by Gareth Bale, Claudio Yacob manages to make a clearance.
The free kick is delivered right-footed by James Morrison from right channel.
Booking Booking for Jan Vertonghen for unsporting behaviour.
Jan Vertonghen gives away a free kick for an unfair challenge on Marc-Antoine Fortune.
The referee blows his whistle to start the second half.
45:00 +2:03 Half time
Half Time The half-time whistle blows.
The ball is crossed by Gareth Bale, blocked by Gareth McAuley. Jermain Defoe takes a shot. Save by Ben Foster.
Jermain Defoe takes a shot. Blocked by Jonas Olsson. Outswinging corner taken by Rafael Van der Vaart from the left by-line, clearance by Youssouf Mulumbu.
Shane Long fouled by Jan Vertonghen, the ref awards a free kick. Direct free kick taken by Graham Dorrans.
Free kick awarded for an unfair challenge on Jermain Defoe by Claudio Yacob. Direct effort from the free kick comes in from Rafael Van der Vaart.
Centre by Aaron Lennon, Youssouf Mulumbu manages to make a clearance.
Unfair challenge on Youssouf Mulumbu by Raniere Sandro results in a free kick. Claudio Yacob restarts play with the free kick.
Free kick awarded for a foul by Jake Livermore on Youssouf Mulumbu. Steven Reid produces a shot on goal direct from the free kick.
Free kick crossed by Rafael Van der Vaart, Gareth McAuley makes a clearance. Inswinging corner taken left-footed by Rafael Van der Vaart from the right by-line, Foul by Gareth Bale on Gareth McAuley, free kick awarded. Direct free kick taken by Ben Foster.
Booking The referee cautions Youssouf Mulumbu for unsporting behaviour.
Youssouf Mulumbu concedes a free kick for a foul on Jermain Defoe.
Gareth Bale challenges Gareth McAuley unfairly and gives away a free kick. Ben Foster takes the direct free kick.
Gareth Bale produces a cross, Aaron Lennon takes a shot. Blocked by Liam Ridgewell.
The ball is swung over by Gareth Bale, Claudio Yacob manages to make a clearance. Effort on goal by Jan Vertonghen from inside the area goes harmlessly over the bar.
The ball is sent over by Steven Reid.
Aaron Lennon delivers the ball, clearance made by Steven Reid.
Kyle Walker produces a cross, clearance made by Liam Ridgewell.
Aaron Lennon crosses the ball, Rafael Van der Vaart produces a right-footed shot from deep inside the penalty area which goes wide of the right-hand post.
A cross is delivered by Gareth Bale, Aaron Lennon takes a shot. Save by Ben Foster.
The ball is sent over by Gareth Bale, Liam Ridgewell makes a clearance.
The ball is crossed by Kyle Walker, Effort on goal by Gareth Bale from just inside the penalty box goes harmlessly over the target.
Aaron Lennon produces a cross.
Jermain Defoe takes a shot. Youssouf Mulumbu gets a block in.
Shot from outside the box by Gareth Bale misses to the left of the target.
Marc-Antoine Fortune gives away a free kick for an unfair challenge on Benoit Assou-Ekotto. Free kick taken by Brad Friedel.
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