Harry Redknapp's side lead Arsenal by a single point in the race for the final automatic Champions League qualifying spot, though their North London rivals can leapfrog the White Hart Lane club by avoiding defeat against Manchester City at the Emirates Stadium on Sunday.
Tottenham, who at one stage enjoyed a 10-point advantage over the Gunners, look to have the easier run-in on paper in their remaining six games, starting with the visit of Norwich City on April 9.
But there are certain to be plenty more twists and turns in the final few weeks of the campaign.
The issue could be further complicated if Chelsea -- who face Champions League holders Barcelona in a two-legged semi-final later this month -- win the competition in May, meaning only the top three in the Premier League will qualify for next season's competition.
A point at a venue where Manchester City, Arsenal and Liverpool have been beaten this season isn't a bad return for Tottenham but it leaves them with just one victory in seven league games.
It might have been different but for a late goal-line clearance from Michael Turner to deny Rafael van der Vaart, after the Dutchman latched on to a pass from substitute Aaron Lennon.
Replays showed the Sunderland defender used a hand to help keep the ball out, in a let-off for the hosts.
Redknapp -- who remains unbeaten in league battles with Sunderland manager Martin O'Neill for 15 years -- threw on forwards Louis Saha and Jermain Defoe in search of a first away league win since December, but the visitors couldn't find a way past the dogged hosts.
Sunderland did an unwanted favour for local rivals Newcastle, who are now just three points behind Tottenham and still in the hunt for a top four finish.
Chances were at a premium before the break as the contest failed to spark into life, Tottenham carving out the best of what few opportunities there were from two unchanged line-ups.
Benoit Assou-Ekotto fired narrowly wide from long-distance after being set-up by Scott Parker, and a shot on turn from Luka Modric 18 yards out saw a comfortable save from Simon Mignolet.
Both sides had half-hearted handball penalty claims turned down: Sunderland defender Phil Bardsley inadvertently halted an Emmanuel Adebayor header with his left arm; at the other end, Tottenham skipper Scott Parker went similarly unpunished for an unwitting use of the hand as he tussled with Craig Gardner for possession.
It was the same pattern of play after the break with the visitors in control but unable to make their territorial advantage pay.
Gareth Bale did well to provide an inviting cut back for Modric, who teed-up van der Vaart, only for the well-placed midfielder to fire over from the edge of the area.
With Sunderland largely trying to catch out Spurs on the break, Bale then planted a header from 10 yards onto the roof of Mignolet's net as the Welshman met an Assou-Ekotto centre from the left.
Bardsley replied, trying his luck from 30-yards but Spurs keeper Brad Friedel saved comfortably enough at the second attempt.
This result meant Sunderland were kept scoreless at home for the first time under O'Neill as they tried to equal their best Premier League finish of seventh place, which they last achieved in 2001.
Source: AFP
Source: AFP