Wenger's greatest humiliation
The sound of Sir Alex Ferguson almost killing Arsene Wenger with kindness may have been the most ominous noise of all for a manager who had just suffered his greatest humiliation.
Wenger still has aspirations to win titles and revisiting one of the great Premier League managerial rivalries - a fanciful notion after Manchester United became the first team to score eight goals against Arsenal since Loughborough in 1896.
So to hear Ferguson expressing genuine sympathy bordering on sorrow for Wenger at Old Trafford, the place where Arsenal once triumphantly confirmed the league and FA Cup double, after an 8-2 mauling only added a further layer of embarrassment to his obvious suffering.
The manner in which United graphically, horrifically in an Arsenal context, illustrated the gulf between the two sides marks down this remarkable Old Trafford match as a watershed moment.
For Wenger it was a performance, or lack of one, that proved the folly of his summer of transfer inaction and for United it confirmed the seeds of their next title-winning side have been successfully sown by Ferguson.
United took to the pitch with a resounding message echoing in their ears from "noisy neighbours" Manchester City after their 5-1 win at Tottenham and answered back with irresistible force to wipe out Arsenal and return to the top of the table on goal difference.
Wayne Rooney's hat-trick took him past 150 goals for the club, Ashley Young scored two stunning strikes and United could have raced into double figures and beyond but for their own carelessness.
With an average age 23, United were youthful, vibrant and laced with pace and power in all parts of the pitch - in other words the template Wenger always craves for his teams.
If Manchester City are going to pose a massive threat, as seems certain, then United look in shape to meet the challenge. They have emerging stars in defence in Phil Jones and Chris Smalling and attacking options to burn - at times they treated Arsenal with merciless contempt.
Wenger cut a despairing figure still locked in various stages of denial in his post-match inquest, flailing against reality by reeling off a list of absentees and how this was only early days. True enough, but Arsenal have made the sort of false start that would make Usain Bolt blush and absenteeism was no excuse for the debacle that unfolded at Old Trafford.
One hesitates to use the word, but there was something rather sad about some of Arsenal's efforts and in Tomas Rosicky and Andrey Arshavin they had two prime culprits. Youngsters like Carl Jenkinson, sent off in the second half, and Francis Coquelin were promoted above their rank through necessity so can be excused, but Rosicky and Arshavin were so poor it almost defied belief.
And then we come to Wenger. A man so admired for his philosophies and past successes, he has bluntly failed to address the serious problems that faced his team after last season imploded on Arsenal.
To hear him talk about how he would like a midfield player and a defender with three days to go before the transfer window closes begged the question why he had not tackled this earlier in the summer when it was clear this was Arsenal's Achilles heel and the world knew Cesc Fabregas would be leaving, followed by Samir Nasri.
The grim evidence that unfolded at Old Trafford was mere confirmation of the holes in the Londoners' side and why Wenger has erred in being reduced to scouring the transfer market at the last minute for quality reinforcements.
Wenger had a valid point when he stressed that the Gunners were without eight players, but Manchester United had men of their own missing - the difference is Ferguson found solutions and strengthened quickly while his counterpart has seemingly prevaricated.
Arsenal's substitutes were more a "Who's He?" than a "Who's Who" - Oguzhan Ozyakup and Gilles Sunu for instance - and for this Wenger must accept responsibility for how he has allowed his squad to thin out.
Many Arsenal supporters, and to a man and woman they were magnificent in the support they gave their battered players at Old Trafford, question the support Wenger is receiving financially from his board.
Suspicions have been raised by offers for Everton's Phil Jagielka and Bolton's Gary Cahill that were never going to be accepted but Wenger insisted at Old Trafford that he has money. The mystery is why it has not been spent earlier.
Liverpool faced accusations that they had paid above the market rate for players such as Stewart Downing and Jordan Henderson. This may be true but they got deals done, beefed up their squad significantly and the benefits are seen in early season results.
The suggestion that Wenger should pay for the current malaise with his job, or that his future is uncertain, is clearly a nonsense. He has earned every right to solve Arsenal's problems but the scale of this loss proved the time for action has arrived - indeed it arrived at the end of last season.
Wenger will have known few darker days - trounced by the team he once toppled with such relish - and he must act swiftly to shed some light on Arsenal's season.