Manchester United still look the title heavyweights but a weak punch cost them dear here. United had been defending diligently a lead seized inevitably by Robin van Persie, resisting Spurs' late storm, until their goalkeeper David de Gea made his one mistake, leaving United only five points clear of Manchester City.
Games at this level can be about fine lines, about a keeper demonstrating total indomitability under sustained pressure. The dropped points will inevitably raise questions over whether United possess the keeper of the requisite character to wrest the title back from City. De Gea showed a frailty at dealing with crosses last season but had improved this term.
Yet deep into injury time here, the Spaniard's punch was poor when attempting to clear Benoit Assou-Ekotto's cross from the left. De Gea was under pressure from Steven Caulker but he still failed to impart sufficient power into his fisted clearance. The ball fell to Aaron Lennon, who picked out Clint Dempsey to equalise. In fairness to De Gea, the error needs setting against some fine earlier saves, particularly from Gareth Bale and Dempsey.
His manager, Sir Alex Ferguson, focused his anger on the officials afterwards, claiming (rightly) that Wayne Rooney was denied a penalty when his heels were clipped by Caulker, but Spurs also had grounds for grievances, not least when Scott Parker felt fouled in the box by Shinji Kagawa.
The result was fair. Spurs had pressed and pressed for an equaliser, eventually celebrating as if they had secured the title. Fans hugged each other. Andre Villas-Boas looked in the mood to break the world squat-thrust record. Dempsey's goal meant so much.
It was deserved reward for their effort. It would have been a particular travesty if the lively Lennon had finished on the losing side. Spurs' development under Villas-Boas is embodied as much by Lennon, all sparky attacking and selfless tracking back, as the regular headline act Bale. In seasons gone by, Spurs might have melted when United took the lead. Here they showed their belief, ignoring the absence of Emmanuel Adebayor at the Africa Cup of Nations, Sandro through that terrible cruciate injury while Jan Vertonghen was struggling with sickness, and could make only the bench. The point - and second-half performance - confirmed Spurs are heading in the right direction under Villas-Boas.
The visitors' dugout was awash with sleet and frustration. Ferguson's team had defended so determinedly and nimbly late on as Spurs tore into them. Rio Ferdinand slid in to block a Jermain Defoe shot and then pushed his head in the way of a Bale strike, diverting it to safety. Michael Carrick and Phil Jones patrolled in front of Ferdinand and company, keeping Spurs at bay. They were defending the points, making another statement of their desire to win a 20th title.
Until De Gea's weak punch failed to clear the danger.
Until then, it had been one-nil to the former Arsenal player. Van Persie has now scored in his club's last five Premier League games, rivalling his best scoring run (with Arsenal in 2009 and 2011). The Dutchman moves so stealthily that here was an opportunity to discover finally whether he really does not leave footprints in the snow.
The icy conditions had briefly placed the game in doubt but United made their desire for it to go ahead abundantly clear. They do not want fixture congestion. Even in the snow, the show must go on. Most of the players were in short sleeves, a few in gloves, but the real sartorial statement came on the bench with Ferguson in a Beanie hat with the United crest at the back.
Ferguson's 4-5-1 tactics had worked for so long. Kagawa played off Van Persie with Danny Welbeck and Tom Cleverley tucking in on the flanks while Jones helped Rafael deal with Bale.
United had actually been slow to find their stride. Lennon was quick to trouble Patrice Evra, even drifting inside after 12 minutes and drawing
a low save from De Gea. Spurs' work rate glistened in the floodlit snowfall. United absorbed the pressure, hitting back to devastating effect after 25 minutes.
Kagawa and Carrick combined in the centre and suddenly red shirts were racing forward. Welbeck glided across from the left, keeping the ball away from the attentive Lennon, before picking out Cleverley on the right. His cross was superb, hoisted to the far post. Van Persie ghosted in, meeting the ball ahead of the sluggish Kyle Walker. Van Persie's header was too fast and well-placed for Hugo Lloris.
This was Van Persie's 22nd of the season but he is so much more than a goalscorer. Moments later, he was back clearing a corner.
Spurs refused to be disheartened. Parker and Mousa Dembele kept pushing them forward. Defoe had a shot saved. Bale, hitherto quiet, then appeared in the centre and let fly with a shot that deviated off Ferdinand. De Gea was diving to his right but somehow managed to reposition his shins to keep out Bale's strike.
Welbeck kept impressing down the left, often linking well with Evra., but Spurs were building. Bale stabbed a left-footed shot over. Dempsey then ran on to Dembele's pass but was denied brilliantly by the legs of De Gea. Parker appealed for a penalty after being brought down by Kagawa.
United should definitely have had a penalty. Welbeck picked out Jones, who stroked the ball towards Rooney, who had replaced Kagawa. The England striker was clearly fouled by Caulker but Chris Foy waved play on.
United were defending well. Ferdinand slid in to block that Defoe shot. Rafael calmly headed a cross back to De Gea. Carrick intercepted a Dembele pass. Ferdinand saw off a Defoe break. Jones blocked a Lennon effort, then hooked a loose ball clear and then outjumped Dembele. But then came De Gea's mistake.