LONDON - Arsenal produced another late show at Emirates Stadium as Kolo Toure rescued a point against Middlesbrough - but it was not enough to send the Gunners back to the top of the Premier League.
After Manchester United beat bottom club Derby 1-0 earlier on Saturday, Arsene Wenger's men knew only victory in the day's late kick-off would be good enough to remain ahead in the title race.
However, a goal from Jeremie Aliadiere against his old club in the 25th minute looked to be sending them to defeat following a determined defensive display by the visitors.
However, Toure nodded in with just four minutes left to earn a share of the spoils.
Boro finished the game with 10 men when substitute Mido was sent off for a high kick on Gael Clichy.
But with the margins for error at the top of the table so slim, a fourth successive draw in the Premier League could yet come back to haunt the Gunners.
It could, though, have all worked out so different had an Arsenal goal from Emmanuel Adebayor not been incorrectly ruled out after only four minutes, when the ball through had come off the boot of George Boateng at the edge of the Boro area.
Slowly Arsenal started to get control of midfield.
Emmanuel Eboue whipped in a cross from the goal-line on the right, which looped over keeper Mark Schwarzer and came off the top of the crossbar.
Arsenal had dominated the opening quarter of an hour, but despite plenty of positive build-up just lacked a telling pass.
Fit-again Robin van Persie - back in the starting XI for the first time since January - showed his rustiness as he completely missed an attempted volley when coming in on the angle down the left.
Eboue then created space for himself on the right side of the box and drilled in a low shot, which Schwarzer did well to deflect behind at the near post.
In a rare moment of action at the other end, Gary O'Neil fired a shot over the bar from 20 yards following a quick break.
Adebayor almost got on the end of a long pass up field by Cesc Fabregas, but the pace just took it too far ahead of the African frontman.
Out of nothing, Boro snatched the lead in the 25th minute.
Schwarzer took a free-kick deep in his own half. A long ball down the left released Tuncay Sanli ahead of the Arsenal defence, who were holding on the halfway line looking to play offside.
The Turk dashed clear and his pass back across the face of goal picked out Aliadiere - who took great delight in knocking the ball into the net.
Arsenal - who had recorded just one win in the last six games - needed a quick response.
Eboue charged down the right and on into the penalty area before going down under a challenge from Boro skipper Emmanuel Pogatetz, but referee Mark Halsey signalled only a goal kick.
Middlesbrough continued to look to move the ball forwards quickly, rather than sit back on their lead.
As half-time approached, Arsenal were making plenty of progress around the Boro penalty area - but again lacked a decisive pass to unlock a determined rearguard.
The home side pressed again at the start of the second half.
Van Persie made space outside the left edge of the penalty area, and drilled a low shot just wide from 20 yards.
Luke Young tripped Arsenal winger Alex Hleb to give away a free-kick on the left.
Fabregas' ball in picked out William Gallas, but the Arsenal skipper could only head over from 10 yards out. However, the offside flag had gone up anyway.
Arsenal continued to have the better possession as the hour mark approached, but without making any real progress.
Adebayor chased a couple of hopeful long balls, most unlike Arsenal as the tension mounted around Emirates Stadium.
Wenger made a double change with 29 minutes left.
Theo Walcott replaced van Persie and striker Nicklas Bendtner came on for full-back Bacary Sagna as Arsenal regrouped.
The changes gave the hosts new impetus, with the crowd responding to the positive tactical switch.
Hleb put Fabregas in, but Schwarzer was out quickly to save at his feet.
With 15 minutes left, a header from Fabregas shaved the outside of the post with Schwarzer beaten - just about summing up Arsenal's afternoon.
Boro seemed content to sit deep and soak up pressure with 10 men behind the ball as the match entered the closing stages.
However, Toure levelled with just four minutes left when his header found its way into the net after Schwarzer and substitute Andrew Taylor collided on the line.
Mido - who had only just come on after 79 minutes - was shown a straight red for kicking Clichy in the face as he went for a high ball.
Arsenal pressed for a winner in four minutes of stoppage time, but had to be content with a fourth successive draw - which could yet prove so costly come May.
