'A David Unsworth penalty and Aiyegbeni Yakubu's sixth goal of the season undid United in a frantic second half, when Pompey matched the expensive quality of their visitors with a battling spirit and a splendid work-ethic which was a credit to their manager Harry Redknapp.
United boss Sir Alex Ferguson will probably not have much thirst for the red wine Redknapp undoubtedly offered after the final whistle. The visitors, in truth, threw it away - just as they did at the end of last season when Pompey inflicted their first victory over them for 46 years at Fratton Park.
Pompey were full value again with every player a hero, even though they lost £2.3million striker Diomansy Kamara and Czech schemer Patrik Berger to injuries before half-time. After looking likely to be overrun in the first 20 minutes and then losing Kamara after little more than half-an-hour, Portsmouth put the block on United's creativity and emerged from the first half at least worth a split-decision.
Ryan Giggs, Alan Smith, Paul Scholes and, especially, Ronaldo had the chances to bury Pompey early on - the Portuguese winger shooting wide with the target clear in his sights from 12 yards after a piece of magic by Wayne Rooney.
Scholes should have scored right after the break, but he thumped his shot straight at Shaka Hislop and United buzzed around the goal for a spell until suddenly, in the 52nd minute, Argentinian defender Gabriel Heinze lost his head and pulled down Fuller in the area at the other end.
Ferdinand snapped and kicked the ball out of the ground when Barry awarded the penalty and was booked for his petulance, while Unsworth stayed ice-cool to ram home the spot-kick.
From then on the match was almost a carbon copy of the siege when United were trailing 1-0 in the second half at the same venue last season.
The visitors did everything but score - Ronaldo's header hit the bar, Smith nudged a shot wide, Hislop caught a collection of shots and Dejan Stefanovic and Arjan de Zeeuw headed a plethora of crosses.
There was action at the other end, though, and with just over 20 minutes to go Hislop's long kick brought a slip from Mikael Silvestre, enabling Yakubu to measure up his shot before steering it home.
United continued pressing, but the barrier was immense and they rarely looked like breaching it.
Ferguson's side have now drawn five times and lost twice in the Premiership - not the form of champions.'