Van Nistelrooy scored 95 league goals in 150 appearances for United between 2001 and 2006, winning the Premier League, the FA Cup and the League Cup in the process.
And in his return to Old Trafford he wasted no time in getting his name on the scoresheet.
The Dutchman is leading the line for Manchester United legends against Barcelona legends this afternoon at Old Trafford.
And the striker didn’t take long to provide the crowd with what they came to see.
Van Nistelrooy fired the Red Devils ahead from the penalty spot on 24 minutes with a powerful low drive into the bottom left corner.
The former Real Madrid star then saluted the Old Trafford faithful before celebrating with his team-mates.
Both clubs have their legends on show in aid of charity.
The teams are wearing black armbands to commemorate the recent terror attacks in both cities, while a minute’s silence was also held before the match.
The ticket sales from the match will also go towards Manchester United Foundation’s work with young people across Greater Manchester.