Aleksandar Kolarov flicked the ball past Joe Hart early in the second-half to give the hosts the lead and that, with time running out, appeared to be that.
Then, as the clock ticked past 82 minutes and City seemingly on their way to another miserable defeat on the road, the Blues grabbed two goals inside three minutes through Yaya Toure and Sergio Aguero to seal a dramatic 2-1 win.
It was the perfect start to 2016, though for long periods it had looked as though it would be anything but a happy start to the New Year.
The meetings between City and Watford have been few and far between over the years and this was only the eighth meeting between the teams at Vicarage Road.
The Blues’ only success at this venue came back in 2002 when Kevin Keegan’s side mustered a 1-0 win, but that was the only victory in the Hornets’ nest with the other six visits yielding three defeats and three draws.
City came into the game looking to end a miserable run of results away from home in the Premier League with just three points taken from a possible 18 and only two goals scored during that run – and with the news Arsenal had moved six points clear filtering through before kick-off, the pressure to win this game cranked up a notch.
Manuel Pellegrini kept the same starting XI from the goalless draw at Leicester while the Hornets made two changes from the 2-1 defeat to Spurs.
The Blues started slowly and were guilty of too many misplaced passes in the opening exchanges.
Twice the prolific partnership of Troy Deeney and Odion Ighalo came close to breaking the deadlock, first when Deeney raced through only to be foiled by an excellent Kolarov challenge, and then when Hart saved well from Ighalo who had spun free of Nicolas Otamendi on the edge of the box.
The warning shots fired, the Blues desperately needed to spark into life before the hosts gained the upper hand.
Kolarov and Kevin De Bruyne hit efforts from distance without troubling Gomes in the Watford goal and David Silva fed Fernandinho just past the half-hour which resulted in a scramble that Raheem Sterling ended with a wild shot.
Then Aguero twice threatened with runs into the box but he was forced wide each time – it was better from the Blues who seemed to be gradually warming to the task but the game reached the halfway point without either defence being breached.
The hosts started the second period brighter with one of two half-chances scrambled clear by the City defence, but a tale of two corners in the space of two minutes, one missed and one scored, changed the complexion of this game.
The Blues went agonisingly close to going ahead when Silva’s corner found the head of Fernandinho who powered the ball inches over the bar on 53 minutes and it was to prove a costly miss.
At the other end, Ben Watson – the man who scored the winning goal against the Blues in the 2013 FA Cup final for Wigan – whipped in a corner that Kolarov inadvertently flicked past Hart and into the net.
City needed to up their up the game or face yet another trip home empty-handed. More worrying was the lack of clear-cut chance that had been created.
De Bruyne found Toure just inside the box with an angled pass on 68 minutes but the Ivorian’s powerful shot fizzed a few feet over the bar and then De Bruyne forced Gomes into his first meaningful save moments later with a low drive from 18 yards.
Time was running out.
Then, after surviving another couple of Watford raids, the game turned completely on its head with two City goals inside the space of three minutes.
The equaliser came on 82 minutes with Kolarov’s out-swinging corner sweetly volleyed home by Yaya Toure from six yards and suddenly City were a different side, vibrant and full of invention again.
Then, with the celebrations among the travelling thousands barely over, Bacary Sagna whipped in a cross from the right and Aguero leapt to head the ball firmly past Gomes for the sweetest of winning goals.
It hadn’t been pretty, but the Blues had dug in, battled hard and never stopped believing.
