Spurs hold Chelsea to thrilling draw
Sigurdsson's well-taken equalizer in the 80th minute earned Spurs a point at a ground where they have a dreadful record but their destiny was out of their hands now, lying fifth behind Chelsea and Arsenal with two games left.
''Obviously with a point we don't depend on ourselves any more, someone else will have to drop points,'' said Tottenham manager Andre Villas-Boas, making his first return to the club that fired him 14 months ago.
A victory would have all but secured Chelsea a place in Europe's top competition for an 11th straight season but it squandered leads given to the team by Oscar in the 11th minute and fellow Brazil international Ramires in the 39th. Emmanuel Adebayor scored a superb first equalizer for Spurs following a run from his own half in the 26th, only his fourth goal of the season.
The result will have gone down well at Arsenal, which is a point ahead of Spurs in fourth and knows it will qualify for the Champions League by winning its final two games - against relegation candidates Wigan and Newcastle in the space of five days next week.
Third-place Chelsea is three points ahead of Tottenham with a vastly superior goal difference, so one win from its remaining games against Aston Villa and Everton will likely be enough, too.
''We had the chance today,'' interim Chelsea manager Rafa Benitez said. ''Twice we had the advantage and we could have killed the game.''
If Spurs do fail to make the top four, they will be hard pushed to keep hold of star forward Gareth Bale, one of the most sought-after players in world football after his brilliant season in which he has scored 20 goals in the Premier League.
He was largely kept under wraps by Chelsea, meaning the visitors were always unlikely to end their winless streak at Stamford Bridge that dates to 1990.
While Bale, a scorer in his last three matches, was quiet, opposite forwards Juan Mata and Oscar were anything but and they combined for the opening goal. Mata whipped in an inviting corner that was headed goalward by Gary Cahill, and Oscar was on hand to glance the ball in at the far post.
Tottenham equalized against the run of play when Lewis Holtby robbed Ramires and set free Adebayor. The striker, preferred to Jermain Defoe up front, ran unchallenged to the edge of the area before curling a tremendous shot over goalkeeper Petr Cech and into the top corner.
Ramires regained the lead for Chelsea by running onto Fernando Torres' pass and poking home a finish but the hosts lived to regret not scoring a third and potential decisive goal during a dominant period at the start of the second half.
Eden Hazard, who later hobbled off, and Mata missed chances and Sigurdsson capped Tottenham's strong finish by collecting Adebayor's deft flick and bending a shot beyond Cech to seal a draw.
''We showed our fighting spirit again,'' Tottenham captain Michael Dawson said. ''We gave them an early leg up and that was disappointing. But we showed the character and the ability we've got.
''Top four is out of our hands again. Hopefully someone does us a favour when they play Arsenal.''