Gundogan's goal was the German's third in the Premier League this seasonManchester City midfield pair Ilkay Gundogan and Fernandino were on target as Pep Guardiola's Premier League superiority over West Ham continued.
City have now won 10 out of 11 top-flight meetings with the Hammers under the Spaniard.
In a game played in a snow-storm before half-time, skipper Gundogan provided the decisive moment after 33 minutes when he turned home a deflected Riyad Mahrez effort at the far-post.
It was the Germany midfielder's third goal of the season - and his second in four league games - and was followed up in the final minute by Fernandinho, who had only been introduced three minutes earlier to tie the game up.
The veteran Brazilian had not scored a Premier League goal since October 2018 but found the target from the edge of the box.
Manuel Lanzini pulled one back with the final kick of the game, which cost Ederson his 100th clean sheet in all competitions but did nothing to prevent City moving back into second spot, six points clear of the Hammers.
The Londoners remain fourth despite suffering successive Premier League defeats for the first time since April.
Weather main threat to City win
The second half was delayed by almost 10 minutes so snow could be cleared from the pitchGuardiola should offer special thanks to head groundsman Lee Jackson and his team for this latest victory.
As half-time approached with heavy snow falling on a pitch already covered in it, there was a real fear the game might not reach its conclusion.
Yet Jackson and his colleagues got to work and with the aid of a half-time interval extended by referee Michael Oliver by five minutes, and the surface was clear again when the game restarted, by which time the snow had stopped.
Jackson's reward was an effective home display, even if it was some way short of show-stopper.
West Ham keeper Lucasz Fabianski denied Gundogan a second and Bernardo Silva's excellent chipped finish counted for nothing thanks to an offside flag.
And Ederson, whose only significant save was turning away a fierce Declan Rice shot, was denied his personal milestone with a goal out of virtually nothing from Lanzini, when West Ham had no time to even think about an equaliser.
'Magnificent' Man City players have not let their levels drop - GuardiolaBelow-par Hammers
Despite losing 22 out of 25 previous away games against the defending champions, West Ham can rarely have gone into such a fixture in more optimistic mood.
Yet they never really got going.
Fabianski was booed by the City fans inside the opening 10 minutes for apparent time-wasting and the experienced Poland goalkeeper was soon earning the wrath of David Moyes for a fluffed clearance that would have resulted in a goal had Mahrez not been offside when Raheem Sterling's block landed at his feet.
Arthur Masuaku's selection ahead of Jarrod Bowen was supposed to provide more protection down the West Ham left flank but City's array of attacking talent just found spaces elsewhere.
Ben Johnson's goalline clearance to deny Mahrez, who also hit the outside of the post, before half-time was followed up by Ryan Cresswell bravely sliding in to turn Gabriel Jesus' goal-bound effort away for a corner. It was effectively Cresswell's final contribution as he continued into the post with such force he needed to be replaced by Vladimir Coufal after hurting his back.
It made no fundamental difference to the flow of the game and West Ham will be thankful for the failings of others that their position in the table remains as it was.
West Ham always in the game against Man City - MoyesWhat's next?
Manchester City's next Premier League game is at Aston Villa on Wednesday, 1 December (20:15 GMT). West Ham entertain Brighton at London Stadium on the same day (19:30 GMT).
Player of the match
RiceDeclan Rice
West Ham United
Squad number41Player nameRice
Squad number10Player nameLanzini
Squad number1Player nameFabianski
Squad number9Player nameAntonio
Squad number22Player nameBenrahma
Squad number31Player nameJohnson
Squad number4Player nameZouma
Squad number15Player nameDawson
Squad number3Player nameCresswell
Squad number20Player nameBowen
Squad number8Player nameFornals
Squad number28Player nameSoucek
Squad number5Player nameCoufal
Squad number26Player nameMasuaku
Line-ups
Man City
Formation 4-3-3
31Ederson
2Walker3Rúben Dias14Laporte27Cancelo
8Gündogan16Rodri20Bernardo Silva
9Gabriel Jesus26Mahrez7Sterling
31Ederson2Walker3Rúben Dias14LaporteBooked at 29mins27CanceloBooked at 61mins8Gündogan16Rodri20Bernardo Silva9Gabriel Jesus26Mahrez7SterlingSubstituted forFernandinhoat 87'minutesSubstitutes
5Stones6Aké11Zinchenko13Steffen25Fernandinho33Carson80Palmer87McAteeWest Ham
Formation 4-2-3-1
1Fabianski
31Johnson15Dawson4Zouma3Cresswell
28Soucek41Rice
8Fornals22Benrahma26Masuaku
9Antonio
1Fabianski31Johnson15Dawson4Zouma3CresswellSubstituted forCoufalat 61'minutes28Soucek41Rice8Fornals22BenrahmaSubstituted forLanziniat 59'minutes26MasuakuSubstituted forBowenat 74'minutes9AntonioSubstitutes
5Coufal7Yarmolenko10Lanzini11Vlasic13Areola16Noble20Bowen23Diop33KrálLive Text
Match ends, Manchester City 2, West Ham United 1.
Second Half ends, Manchester City 2, West Ham United 1.
Goal! Manchester City 2, West Ham United 1. Manuel Lanzini (West Ham United) right footed shot from outside the box to the top left corner.
Attempt missed. Tomas Soucek (West Ham United) header from the right side of the box misses to the right. Assisted by Vladimir Coufal.
Foul by Gabriel Jesus (Manchester City).
Jarrod Bowen (West Ham United) wins a free kick on the right wing.
Offside, Manchester City. Fernandinho tries a through ball, but Bernardo Silva is caught offside.
Goal! Manchester City 2, West Ham United 0. Fernandinho (Manchester City) right footed shot from the centre of the box to the bottom left corner. Assisted by Ilkay Gündogan.
Corner, Manchester City. Conceded by Ben Johnson.
Substitution, Manchester City. Fernandinho replaces Raheem Sterling.
Corner, West Ham United. Conceded by João Cancelo.
Kyle Walker (Manchester City) wins a free kick in the defensive half.
Foul by Manuel Lanzini (West Ham United).
Attempt blocked. Rúben Dias (Manchester City) header from the centre of the box is blocked. Assisted by Riyad Mahrez with a cross.
Corner, Manchester City. Conceded by Pablo Fornals.
Attempt saved. Ilkay Gündogan (Manchester City) left footed shot from the left side of the box is saved in the centre of the goal. Assisted by Raheem Sterling.
Attempt saved. Declan Rice (West Ham United) right footed shot from outside the box is saved in the centre of the goal. Assisted by Pablo Fornals.
Foul by Rúben Dias (Manchester City).
Michail Antonio (West Ham United) wins a free kick on the left wing.
João Cancelo (Manchester City) wins a free kick in the defensive half.
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