It was 10 April, Arsenal had just beaten Blackpool and the trauma of what history may record as a defining fortnight was forgotten as Arsène Wenger declared Manchester United and a seven-point gap could be overhauled in the title race. But 160 days on from Arsenal's only Premier League away win in 10 attempts, their manager could not summon the conviction that a top‑four finish remains achievable.

Two weeks in which Arsenal blew the Carling Cup final and were knocked out of the Champions League and FA Cup had a less demoralising effect on Wenger than this summer's talent drain and a "terrible" – his word – start to the domestic season.

Arsenal's previous trip to the north‑west had produced the club's worst defeat in 115 years. With eight senior players missing that fateful day at Old Trafford, and the champions rampant, Wenger could make allowances. Not here. Two own goals, a marginal offside tap-in and an overlooked penalty appeal by Theo Walcott helped Blackburn off the foot of the table and eased the pressure on their manager Steve Kean. And yet defeat was thoroughly deserved for Arsenal once again.

"This is not more humiliating [than the 8-2]. I do not have the measurement of humiliation," Wenger said. "It is frustrating more than anything else, because we had the potential to win. We dominated the game but in our weak moments we were not strong enough to resist. We didn't have many weak moments in this game but every time we had one, we paid for it."

Only five members of the team who played at United started at Ewood Park but Arsenal's weakness was unerringly familiar; namely a complete lack of leadership and class in defence. Robin van Persie did create and cajole on this occasion, Alex Song and Mikel Arteta provided the composure and imagination so lacking at Old Trafford and Arsenal crafted four fine openings in stoppage time to salvage a point from an enthralling contest. But their foundation was shambolic and Blackburn, adopting the tactics of an away team, granted Arsenal possession in harmless wide areas before picking them off at will in the second half.

The day began with a few hundred disgruntled Rovers fans marching through a downpour in protest at the team management. Flyers reading "Kean Out" littered the gutters outside and when Gervinho swept Song's incisive early pass into the far corner, the Scot must have feared a revolt inside Ewood Park too.

Instead, thanks to the resilience of Chris Samba, Scott Dann and Paul Robinson, the predatory instincts of Yakubu Ayegbeni, and Arsenal's generosity, the Rovers manager found himself in the bizarre position of defending Wenger after the game. "What that man has done for the game and what he's done for Arsenal is sensational," Kean said. "To even question his leadership of the club is frightening."

Yakubu's nonchalant equaliser ended a dominant Gunners opening that seemed to indicate that the Old Trafford result was an aberration and transfer-deadline day a fresh start. Arteta's first goal for the club brought a deserved interval lead only for his defenders to forget the basics of nullifying Rovers thereafter.

A Rubén Rochina free-kick was not dealt with at the front post and the ball trickled in off Song's knee. Yakubu converted his second after Laurent Koscielny failed to deal with a Junior Hoilett corner.

Finally, with Bacary Sagna off injured and Martin Olsson introduced against the vulnerable Johan Djourou, Kean's substitution worked to perfection as the Swede's cross struck Koscielny for a second own goal. Marouane Chamakh's textbook header brought palpitations to Blackburn, but no consolation to Wenger. "You can't say you have no worries when you see a performance like that," he said later.

Kean, with his employers watching from the directors' box, had every reason to savour the release of victory. "It can be a lonely place if you don't have the backing at home and the backing with your owners and the backing of your players," he said.

"But I've not felt that. I've had backing in all those areas, so I've not been lonely. Hopefully the 1% of fans who were demonstrating will go home happy because the other 99% who didn't demonstrate were certainly behind us."

The final question was to Wenger. Does he expect to finish in the top four? "I expect to do well in the next game," he replied, and walked away. Maybe he felt it was too early for rallying calls. Or maybe he was still coming to terms with the evidence of the game and was just being realistic.