After two controversial defeats and an equally contentious draw, Middlesbrough got their own back on Manchester United at Old Trafford to blast the Barclays Premiership title race wide open.
Mark Viduka's diving header in first-half stoppage time proved enough to earn Boro a point, which leaves Chelsea knowing five wins - including the key clash with United at Stamford Bridge on 9 May - will confirm a hat-trick of championships.
A bad, bad night for United was made even worse by the knowledge Rio Ferdinand is almost certainly out of Tuesday's Champions League semi-final with AC Milan after aggravating the groin injury he suffered against Watford last weekend.
With half a dozen key men missing Alex Ferguson's squad are being tested as never before. And on this evidence, they do not have the answers.
Boro were worthy of at least a point and with a debatable penalty call going against them as on every other occasion they have faced United this term, gained adequate reward for their efforts.
For a while in the second half it looked as though they might even win as United's defence, ripped to shreds by injury, threatened to disintegrate completely.
In the end, the hosts managed to assert themselves and claim a point which at least keeps their noses in front of Chelsea, who will close to within a point with victory at Newcastle tomorrow.
But they can feel Jose Mourinho's breath on their necks now and it will take something special to shake him off.
Ferguson had not wasted the opportunity to voice his concerns about the tactics Boro would adopt, or the 'paranoia' which has gathered on Teesside about the conduct of Cristiano Ronaldo.
In the end, the United boss had far more to worry about than that, especially as Boro were no more or less robust than any other Premiership side in their efforts to halt the Portugal winger.
Very rarely in a stupendous season that looks set to be rewarded with the PFA Player of the Year award tomorrow night has Ronaldo been as subdued as he was in the opening period.
The absence of Ryan Giggs, rested ahead of Tuesday's Champions League semi-final with AC Milan, might have been a contributing factor, as it allowed the Boro defence to concentrate their attentions on him knowing the other winger, Kieran Richardson, is not blessed with quite the same stellar talent.
Richardson is not exactly the most popular player among the Red Devils fans and was actually booed prior to last week's FA Cup semi-final win over Watford.
Yet, just as the England international was on target at Villa Park, so he was responsible for United's early opener.
In a sense, Richardson was pinching his first Premiership goal of the season off Wayne Rooney given it was the former Everton striker who had charged onto Paul Scholes' inspired lofted pass that caught Jonathan Woodgate on his heels.
However, as Rooney had taken the ball a touch wider than he would have liked as he swept past Mark Schwarzer, it was probably just as well Richardson was on hand to tap home.
With less than three minutes on the clock, it must have been the start Ferguson dreamed of.
But instead of giving way to a cruise and the chance to give a breather to some of their key men, United merely found themselves in a whole heap of trouble.
Rather than laying back and awaiting the slaughter, Boro forced themselves into the game.
Although Edwin van der Sar had not actually been properly tested before Viduka struck, the visitors had enjoyed more than enough of the play to thoroughly merit their equaliser.
Ferdinand had already been clutching his groin in discomfort before his former Leeds team-mate got in front of him to meet Stewart Downing's cross. Whether it made any difference is difficult to assess but it was quite telling Ferdinand did not appear for the second-half.
Neither did Richardson as Ferguson introduced Giggs, no doubt hoping the Welshman's experience would inspire United to greater efforts.
Boro though were in no mood to let their hosts off the hook and Viduka should really have put them in front when he wriggled past Wes Brown, who by now was being partnered by John O'Shea with Darren Fletcher again a makeshift right-back, but fired a close range effort straight at Van der Sar.
The Dutchman flung himself in the way of Ayegbeni Yakubu's angled effort shortly afterwards as United's free-flowing style continued to unravel before Ferguson's eyes.
An impudent piece of skill from substitute Ole Gunnar Solskjaer, who flicked the ball away from Schwarzer as he was about to punt clear then tapped into an empty net, only earned the Norwegian a yellow card.
And though Rooney and Carrick went close near the end, a winner would not come.
United survived a late scare when O'Shea was not punished for a challenge on Dong Gook Lee in the penalty area.
