The irony of one of Liverpool's most battling displays of the season helping arch rivals United end the weekend nine points clear following Saturday's 1-0 win at Fulham will not be lost on either set of fans but their draw was fully deserved.
Second-placed City have dropped points twice in a week following a 0-0 draw at bottom side Queens Park Rangers and only the most avid fan will think the champions can overhaul United now despite last season's stunning fightback.
"Liverpool played a good game but we conceded two goals, stupid goals for me," City boss Roberto Mancini told Sky.
With 13 matches remaining, United also have a better goal difference by three but it would have been even worse for City had Argentina striker Aguero not produced a moment of magic in an engaging game 12 minutes from time.
Edin Dzeko had given City the lead midway through the first half and slightly against the run of play when he slotted in James Milner's low cross from close range.
The visitors were unlucky to be behind after Daniel Sturridge had been denied by a last-ditch tackle from Pablo Zabaleta among other Liverpool chances but the former City front-man made it 1-1 after 29 minutes with a fine finish.
He fired in a crisp strike from 25 metres among boos from the home fans with Dzeko lying on the ground following an earlier incident. However, the referee rightly ruled it was not a head injury and play was not stopped.
Dzeko was arguably fouled in the build-up but he was protesting on the ground as much as being injured and the Bosnian was subsequently booked for dissent to the linesman.
Sturridge, given his big break at City before leaving for Chelsea and then Liverpool, refused to celebrate his goal but the away fans were soon almost cheering again when Zabaleta's bad backpass just went wide of Joe Hart's post.
Seventh-placed Liverpool, gradually improving under Brendan Rodgers despite last weekend's FA Cup loss at third-tier Oldham Athletic, also managed a 2-2 draw at Arsenal on Wednesday but have not beaten a side in the top half of the league this term.
UNGUARDED NET
Any hopes of doing so against the champions after a bright first half seemed to have been dispelled by City's improved display after the break.
However, out of nowhere Gerrard chested the ball down 30 metres from goal following a clearance from the box and sent a fierce strike into the corner of Hart's net.
City were not to be outdone, though, as Liverpool goalkeeper Pepe Reina came charging out of goal and the box near the left byline and Argentina's Aguero somehow clipped the ball past the Spaniard and into the unguarded net.
Tottenham Hotspur midfielder Gareth Bale earlier showed absent strikers how it was done by blasting in a 67th-minute winner in a 1-0 success at 10-man West Bromwich Albion.
The victory for fourth-placed Spurs, which came despite their only available forward Jermain Defoe limping off in the first half, put them a point behind Chelsea in third after Rafael Benitez'
