Rooney reaps the reward of 'change in mentality'

While the new England captain was in the directors' box at Old Trafford, busy with his mobile phone, the man who is the best bet to become Rio Ferdinand's long-term successor was out on the pitch, at the opposition's throats.

The kind of indiscipline that led to Ferdinand's suspension would, you suspect, have concerned Fabio Capello as much as John Terry's sleeping arrangements. However, once the World Cup is done and the England manager wants a leader for the long term, Rooney increasingly looks the part. After all, what motivated Glenn Hoddle to bestow the captaincy on Alan Shearer was his belief that the armband belongs to the best player.

Unlike on his last league appearance at Old Trafford, when he put four past Hull City, Rooney scored only once. Portsmouth undid themselves with three own goals, taking the number of times Manchester United's opponents have put through their own net this season to nine.

Nevertheless, while Portsmouth spent the opening 40 minutes attempting to cling on to any kind of foothold in the game, Rooney probed and pushed and once his header ensured he has now equalled his best tally of goals for a season – 23 – even those who had travelled from the South Coast to support a club vandalised by a succession of owners realised the afternoon was over. However, they could not have anticipated how abject the collapse would become.

The influence Rooney is exerting is not far short of the spell woven by Cristiano Ronaldo in the astonishing 2007-08 season in which he scored 42 times for the team that were denied the chance of a second Treble by a rather better Portsmouth side than this one. For the record, Ronaldo's 23rd of that season came at Reading on 19 January.

"We were a bit angry and frustrated because we knew we could win the game easily," Patrice Evra remarked of the period before Rooney converted Darren Fletcher's cross. "Rooney understands what the team needs. He is getting his just deserts because he is more mature and now he concentrates on staying around the box. He has not lost any desire to press the ball but now he knows he has to score a lot of goals because Ronny [Ronaldo] has gone. He has changed his mentality. Now he wants to score and be a killer."

Portsmouth seemed ready to die. Today, they may be without electricity at their training ground because of unpaid bills but the lights are going out all over the club. Hassan Yebda, who said that he hoped Rooney was not in this sort of form when Algeria meet England in Cape Town, added that unless Portsmouth could overcome Sunderland at Fratton Park tomorrow, the fight against relegation would be practically unwinnable. "We know it is our last chance," he said. "Maybe the pressure will be good for us."

That appears little consolation for Avram Grant, who at Stamford Bridge was used to working for an owner interested in pumping money into the club rather than a succession of men selling anything not nailed down to the boardroom floor. "I don't have the right word to describe it in English. You have to deal with things that have no connection with football," he said. "At Chelsea, I had to deal with a big, big challenge and do things that nobody expected. But at Portsmouth we have to do more than win games, we have to keep the club alive."

Manchester United (4-4-2): Van der Sar; Neville, Brown, Evans, Evra; Valencia, Fletcher (Gibson, 66), Carrick, Nani; Rooney (Diouf, 66), Berbatov (Owen, 66). Substitutes not used: Kuszczak (gk). Park, F Da Silva, De Laet.

Portsmouth (4-5-1): James; Vanden Borre (Boateng, 61), Ben Haim, Wilson, Rocha; Webber, Mullins, Hughes, O'Hara (Yebda, 74), Belhadj; Piquionne (Owusu-Abeyie, 66). Substitutes not used: Ashdown (gk), Finnan, Dindane, Basinas.

Referee: L Mason (Northants).

Booked: Manchester United Diouf; Portsmouth Ben-Haim, O'Hara, Webber, Boateng.

Man of the match: Berbatov.

Attendance: 74,684.