Diaby double inspires 'lucky' Gunners in rout

Arsenal 4 Portsmouth 1

Credit where it is due. A week after four officials all failed to see Freddie Sears score for Crystal Palace Steve Bennett, eyes still sharp at 48, turned the usual critical dictum about referees on its head. He was virtually the only person in the Emirates who recognised that John Utaka was not felled by William Gallas in what had seemed the game's pivotal moment.

Utaka outstripped Gallas as the pair ran towards Marc Wilson's long ball, only to tumble to the ground by the Frenchman. Three minutes later, Gallas killed off Portsmouth's unexpected resistance as he extended Arsenal's lead to 3-1.

Portsmouth manager Paul Hart was as astounded as he was furious. "It was a poor decision and I can't understand how [Bennett made it]," Hart said. Even the famously one-eyed Arsène Wenger could only suggest the offence was not as clear cut as it seemed, adding he feared Gallas would be sent off.

It took Match of the Day to ascertain that Utaka had tripped himself up. Prolonged viewing of replays suggested he may, possibly, have done so because Gallas' left calf had brushed up against his right, but even that was inconclusive. Besides, with Gallas' eyes fixed firmly on the ball, a red card would have been unjust.

Such was the confusion that, bizarrely, Gallas himself, according to Utaka, admitted he should have gone. "I asked Gallas afterwards and he said to me it was a foul," said Utaka. "He was smiling. It changed the game. It could have been 2-2 and the game could have gone either way. He pulled me from behind after I ran past him. I was one-on-one with the keeper. It's a red-card offence. It's like everything is going against us."

That, at least, would seem true. On the opening day they were beaten by a rogue deflection off Fulham's Bobby Zamora. In midweek they lost to a debatable last-minute penalty at Birmingham. All to a backdrop of player sales and an ownership vacuum.

Club officials insist the latest takeover bid, led by chief executive Peter Storrie, will be settled "within a few days". Hart has his shopping list ready, but is wisely taking nothing for granted. First he, and Fabio Capello, await the results of today's scan on a new knee injury for David James. The hope is that it is just "bone-bruising". James's incapacity means a fifth of Hart's already-depleted squad is injured. Asked if he believed the old cliché about fortune evening out over a season, Hart replied: "If it does, we're going to have a great Christmas."

Arsenal are having a great August. Three wins, 12 goals, quite a start. They are, though, enjoying a certain amount of fortune. In an effort to recreate the bond their supporters felt with Highbury, and presumably increase the decibel level, Arsenal have launched what the club describes as "the Arsenalisation" of the Emirates. This will include visual installations celebrating some of the club's past players and achievements. "We have to make the place somewhere where you can feel the history of the club," said Wenger.

One of the old traditions already appears in place. The "lucky Arsenal" tag is more than 70 years old, but seemed as relevant as ever on Saturday. Not only did Bennett exonerate Gallas, when on another day he could easily have been dismissed, there was a suspicion of offside about the Gunners' first and third goals. Furthermore, Gallas, having inadvertently scored off his back at Celtic in midweek, fluked the latter strike as well, off his calf and face.

Hart deserved better luck, not least because he diverged from Portsmouth's usual practice of simply defending in numbers at Arsenal. Hart took a bolder approach, seeking to nullify Arsenal's new 4-3-3 formation by aping it. The problem with matching up is that the game becomes a test of talent as much as organisation – and Arsenal have more talent. That was illustrated when Eduardo skipped past Wilson on the left before setting up Abou Diaby. Three minutes later, the midfielder headed a Portsmouth free-kick clear of his own six-yard box, then showed shades of Usain Bolt as he sprinted 100m to sweep in a cross from Emmanuel Eboué.

Younes Kaboul beat a flat-footed Manuel Almunia to head in Nadir Belhadj's lofted cross but Gallas, then Aaron Ramsey, settled the issue. The only cloud on Wenger's horizon was the early departure of Cesc Fabregas with a tender hamstring. A pull would rule him out for three weeks, which includes Saturday's visit to Old Trafford. Either way, he seems sure to be rested on Wednesday when Arsenal complete the formality of easing past Celtic and into the Champions League. They are in rich form, with the likes of Samir Nasri to add. Suddenly the Gunners are eyeing the return of another tradition, trophies.

Arsenal (4-3-3): Almunia; Eboué, Gallas, Vermaelen, Gibbs; Fabregas (Ramsey, h-t), Denilson, Diaby; Arshavin (Merida, 71), Van Persie, Eduardo (Bendtner, 71). Substitutes not used: Mannone (gk), Sagna, Song, Clichy.

Portsmouth (4-3-3): James (Begovic, 76); Wilson (Vanden Borre, 70), Kaboul, Distin, Belhadj; Mokoena, Mullins, Kranjcar; Piquionne, Kanu (Nugent, 67), Utaka. Substitutes not used: Hughes, Basinas, Ward, Ritchie.

Referee: S Bennett (Orpington).

Man of the match: Diaby.

Attendance: 60,046.