Collins scored the bizarrest of own goals, slicing Jesus Navas' cross in off the crossbar from the edge of his own box, before Aguero sealed the points 15 minutes later in a wonderful team move ending in the a classy finish from close range for the Argentine, now on 101 goals for his club.
The occasion was somewhat spoiled, when Citizens midfielder David Silva went down, motionless and after eight minutes of on-field treatment, was stretchered off to a standing ovation.
The result, while alleviating some of the pressure on Manuel Pellegrini, adds to the stress of Sam Allardyce's role as West Ham manager. The result sees City go just a point behind their local rivals, who beat them last weekend, while West Ham fall behind Stoke City into 10th.
The hosts needed to start well and they did, applying high pressure from the off. David Silva came the closest within the opening 10 minutes, when the Spaniard picked up the ball, but fired just over, much to the relief of the visiting supporters.
City absolutely dominated, in every aspect, during the opening 20 minutes, boasting a staggering 75% possession. Aleksandr Kolarov had a free-kick clip the wall, before spinning agonisingly past the post, though the home fans only had to wait a couple of minutes more the crucial breakthrough and what a strange situation it was. Navas won a header on the half-way line, before surging, rapidly, down the right. The Spaniard then swung in an early cross towards Sergio Aguero in the box, but James Collins' clearance went horribly astray, looping over the head of the outstretched Adrian and in off the crossbar.
City didn't let up after their goal and continued to press hard, with Navas finding Silva in the box, but the latter's shot was blocked from close range.
West Ham's solitary first-half chance fell to Carlton Cole, as the striker capitalised on Martin Demichelis' defensive frailty, but the onrushing Joe Hart was on hand to clear the ball away.
It wasn't long before the champions had another - this time through their top scorer, Aguero. After a swift counter-attack, the Irons' defence found themselves outnumbered, as the Argentine exchanged a one-two with Jesus Navas, before placing the ball calmly past the helpless Adrian, as City made it to two in style.
City almost had a stupendous third, just four minutes into the second half. After great link-up play between Sergio Aguero and Yaya Toure, plus some neat trickery from veteran midfielder, Frank Lampard, the former tried his luck, but the Argentine was denied by a great save.
West Ham's final chance for consolation fell to Ecuadorian striker, Enner Valencia in the last few minutes, when he skewed his shot narrowly wide of the post, pretty much capping off a frustratin afternoon for the travelling East Londoners.
Manchester City now sit seven points clear of fifth-placed Liverpool, albeit having played a game more, almost guaranteeing their Champions League spot for next season. A pretty relieving outcome in the end City fans, but if you'd have told the champions in August that they'd be in for a trophyless season, where they only just scraped top four - they'd have laughed in your face and rightly so. But hey, that's the Premier League.