On what was his 94th City appearance, De Jong put the hosts ahead in the 10th minute, powering the ball into the corner of the net from outside the area after the Hammers had failed to deal with a corner.
The delight of the Holland international, who joined City from Hamburg in 2009, was clear and he told www.mcfc.co.uk: "The ball bounced off one of the West Ham players and came down to the edge of the box. I was standing there so I saw the opportunity to shoot and this time finally it went into the net. The relief was there."
He added: "The boys had been asking me when I was going to score my first goal and saying I had lost my touch, and all sorts of thoughts had been getting into my head.
"So it is nice to score a goal to make sure your side is leading 1-0. It was a personal victory as well."
Pablo Zabaleta - another rare goalscorer - doubled City's advantage on the quarter-hour mark with a shot that went in via Lars Jacobsen, before Demba Ba pulled one back for the visitors in the 33rd minute.
City captain Vincent Kompany, whose embrace with Mario Balotelli before kick-off indicated there was no problem between the two players - despite reports of a training-ground bust-up - was pleased De Jong and Zabaleta got on the scoresheet - even if it leaves him as one of only two outfield regulars at the club without a goal this season, alongside Jerome Boateng.
"I was happy to see Nigel score because he really has been looking for that goal for such a long time," Kompany said. "I know he can score because I played with him at Hamburg and he did there.
"I hope that will trigger his account now and who knows, maybe we will see five or 10 goals a season from Nigel! He can handle the pressure.
"We joke about things like this but it's also a challenge. We joke about Zaba as well, and obviously he has also done it now. I had better start working on it now - I can score as well, so it can't be that long before I get one."
Source: PA
Source: PA