More importantly, it added the scalp of the Premier League champions to those of Liverpool and Chelsea, that were collected earlier this season. And they are yet to face Arsenal.
So, rather than being painted as an industrious team full of scrappers, not afraid to launch the long ball when required, O'Neill thinks a more kind description might be in order.
"There is an ability within our squad that sometimes gets overlooked," said the Northern Irishman.
"People looked at our away results last season and decided we were a counter-attacking side. There is nothing wrong with that. Manchester United have won championships like it.
"We have also tightened up defensively.
"I know we have improved. A couple of years ago we could not have performed like we have been."
There are a number of key men - Brad Friedel for a start. The American had a quieter evening than he might have expected on Saturday, but needed to produce an excellent late save to deny Dimitar Berbatov an equaliser.
James Milner was singled out for special praise by Sir Alex Ferguson, which must make the Villa Park faithful feel slightly queasy, wondering whether it might be the first step towards a bid for the former Leeds star.
Stewart Downing's discipline has not gone unnoticed either and it was the winger who was alert enough to boot a Nemanja Vidic header off the line when the Serbian thought he was going to score.
Agbonlahor clearly likes facing United given he has now found the net against them in four successive seasons, while at the back Richard Dunne has proved to be a very astute buy from Manchester City.
Indeed, the sight of Dunne featuring in a team currently operating at a higher level than their own must have most City fans scratching their heads given his replacement at Eastlands, Joleon Lescott, was acquired at the not inconsiderable sum of £22million.
After leaving City disillusioned at the way executive chairman Garry Cook was handling a club he still has a strong attachment to, Dunne is delighted at the collective unity he has found at Villa.
"We have a really good atmosphere in the dressing room," he said.
"Everyone works hard for each other. Everyone is prepared to put their foot in.
"You could see that by the way we defended. Manchester United are champions for a reason. It is taken for granted that you will not go home with a victory without everyone doing their bit when you come under the cosh."
Ferguson was left grumbling at the amount of time added on by referee Martin Atkinson, but O'Neill claimed Villa deserved their good fortune, having had victory snatched from them in the corresponding fixture last term when Cristiano Ronaldo's late equaliser paved the way for a season-defining stoppage-time winner from Federico Macheda.
It left United to go away and lick their wounds ahead of Tuesday's crucial encounter with Wolves, and Villa to reflect on the strides they have made by coming through a bizarre weekend of results with their position enhanced considerably.
Not that O'Neill was letting an Old Trafford win go to his head.
"I have not enjoyed a game for about 20 years," he responded, when he asked whether he had enjoyed the contest.
"Maybe when we have won the number of games Manchester United have over the last half century we will have something to boast about.
"Until then, we will just try to hang in there for as long as we can because we know the teams who have tended to rise to the top positions will eventually be expected to do so.
"Ourselves, Manchester City and Tottenham are very strong and winning matches like this is bound to do our confidence good. But that could easily be eroded at Sunderland on Tuesday and we have more tough fixtures after that, so there is no point in us getting carried away."
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