A staggering 69,591 and brought in around £2m in receipts for what is likely to be Roy Keane's last appearance last appearance at the Theatre of Dreams.
After 12 largely success-filled years with the club, there were plenty of United fans in the crowd but the near 23,000-strong Celtic contingent showed how much Keane is revered in Glasgow, even though he has only been at Parkhead for five months and will now go on a short holiday with his family before deciding whether to extend his career by one more year.
As predicted, Keane, who made his entrance through a guard of honour from both sides accompanied by his five children, played 45 minutes for each side.
By far the 34-year-old's most productive work came during the second period, when he was wearing the red shirt of United.
In fact, it was almost like turning the clock back a few years as Ryan Giggs, Paul Scholes, Ole Gunnar Solskjaer and Gary Neville lined up alongside the man they shared so many glory days with.
It should be no surprise that two of them - Scholes and Giggs - combined to set up Cristiano Ronaldo, the player whose reported training ground row with Van Nistelrooy is said to have triggered the Dutchman's exit.
Ronaldo took his 55th-minute chance with clinical efficiency, unlike the effort he blazed over shortly afterwards.
It was a deserved success, given United, with Rio Ferdinand deployed in midfield in direct opposition to his old skipper, dominated the opening stages, with Giuseppe Rossi, Louis Saha and Ronaldo all going close.
Another United old boy, Dion Dublin, was only denied an equaliser by a brilliant point-blank save from Edwin van der Sar, who, like Keane, had been introduced at half-time following Everton-bound Tim Howard's last Red Devils appearance for at least 12 months.
But this was Keane's night. And while there may have been at least one physical disagreement between the two biggest contingents of supporters in the British game, they were united in their acclaim of one of the finest talents Ireland has ever produced.