The Reds defied the so-called Fratton Park hoodoo to claim a first league win of the season, thanks to United's scorer from the opening game against Newcastle - Darren Fletcher.
Whether Fletcher keeps the credit may yet be decided by the Dubious Goals Panel but there was nothing dubious about the outcome. The Reds were superior to Portsmouth, especially in the final third, even without Cristiano Ronaldo, the man who scored twice on the Reds’ last win on this ground in 2005/06.
The champions were forced into several injury-enforced changes. Patrice Evra deputised for Ryan Giggs on the left flank while Anderson made an instant return in Michael Carrick's central role, barely 24 hours after flying back to England from the Beijing Olympics. Also back in the UK and back in the side was Carlos Tevez, who missed the Newcastle match after a family bereavement.
Portsmouth took just 13 seconds to fire the first shot - Papa Bouba Diop bouncing one just wide of Edwin van der Sar’s right-hand post - but it took them an awful lot longer to seriously look like scoring.
United were always dangerous with Wayne Rooney and Tevez linking up in attack again and Paul Scholes spraying passes left, right and centre. One exquisite ball wide to Wes Brown on the right flank led to Rooney's first shot on goal, into David James' midriff early on. Scholes’ other trademark came to the fore in the 19th minute when he unleashed a missile after being teed up by Rooney at a direct free-kick. James dived to his left and dealt admirably with the slight swerve to parry the ball away.
A physical first half was not without its casualties - Tevez was on the receiving end of Diop’s bookable challenge shortly before Brown left the field for treatment to his right eye after being caught in a battle between John O’Shea and Peter Crouch. The former Liverpool forward was close to pulling the trigger