In seven minutes at White Hart Lane and 45 minutes at Old Trafford the race for the much-prized top four finish in the Premier League was blown wide open.
Tottenham re-discovered their scoring touch against Manchester City while Aston Villa were in Manchester in name only as Robin van Persie secured the championship for United.
And it is the champions who could now hold the key with their matches against Arsenal on Sunday at The Emirates and against Chelsea at Old Trafford seven days later.
If it comes down to goal difference then the loser from the three chasing the two available spots will be Tottenham. Thursday nights and Sunday afternoons will beckon for Andre Villas-Boas and his men next season in the unwieldy Europa League.
And yet...
If Sir Alex Ferguson is to be taken at his word - and it is a man with a brave heart who would not - then United will give their all at Arsenal.
But history and common sense tell you to back the team with the incentive and that team is Arsenal. Just lately - and possibly all too late - Arsenal have mastered the art of winning when not exactly impressing. Witness their victory at Fulham last Saturday.
It is a decent enough habit at this stage of the season and it may be enough to secure three points. That may not be the result Chelsea want.
Sir Alex would abhor the thought of losing two matches in a row and his famously-uneasy relationship with Chelsea manager Rafa Benitez will come into the equation.
Anything he can do to undermine the ambitions of Benitez is fine by him. Especially after their FA Cup win against United. Chelsea also have the distraction of the Europa League semi-final against Basel.
Tottenham? Their problem is that - a home game with Southampton apart - they have four matches against sides at opposing ends of the table.
Wigan, Stoke and Sunderland in the relegation dogfight and Chelsea away. And their record at Stamford Bridge is unlikely to inspire confidence.
It is all boiling up nicely and Sir Alex will love the fact that his men have such a big part to play.
For me, there will be one point separating the three - Arsenal on 71 points and Chelsea and Tottenham with 70.
Currently, Chelsea are 14 to the good over Tottenham when it comes to goal difference so it looks like Tottenham will pay the price for their lack of conviction in front of goal.
If Jermain Defoe and Gareth Bale have been absent, they have struggled. There has been an over-reliance on the pair and that could be the crucial factor.
Over to you Sir Alex...