Pep Guardiola's men extend their winning run to 15 games in all competitions after they beat Swansea 3-1 in the FA CUP match.
Manchester City has broken the English football record for consecutive wins by a top-flight club by beating Swansea 3-1 to reach the FA Cup quarter-finals.
Kyle Walker, Raheem Sterling and Gabriel Jesus were on target for the visitors, who extended their winning run in all competitions to 15 games on Wednesday.
Victory was also Pep Guardiola's 200th in 268 games as City boss, with the Premier League leaders still on course for a historic quadruple of trophies.
Guardiola's men hold a five-point lead with a game in hand at the top of the Premier League, face Tottenham in the League Cup final in April and resume their challenge to win a first Champions League in the last 16 against Borussia Monchengladbach later this month.
'Not easy record to break'
"It is amazing for ourselves, we cannot deny how pleased and proud we are to break this record," said Guardiola.
"Records are there to be broken, but they have to do well [to beat it].
"It is not easy in the modern era to make 15 wins in a row."
Despite the congested schedule, Guardiola characteristically named a strong side for the trip to South Wales with Sterling, Rodrigo, Bernardo Silva and Ilkay Gundogan retaining their places from Sunday's 4-1 win away to Liverpool.
Walker has lost his place as first choice right-back due to Joao Cancelo's excellent form.
The England defender took his chance to impress with a rare goal to open the scoring on 30 minutes when his tantalising cross avoided everyone in the middle and nestled in the bottom corner.
City quickly turned their complete control of the game into a commanding lead inside the first five minutes of the second half.
Firstly, Rodrigo released Sterling to slot home his 11th goal of the season with a calm finish.
Jesus then controlled and slammed home Silva's header back across goal, allowing Guardiola to replace Sterling, Silva and Gundogan early with an eye to Tottenham's visit to the Etihad on Saturday.
But Rodrigo hobbled off with an ankle injury 20 minutes from time that will concern the City boss.
Morgan Whittaker pulled a goal back for the Swans 13 minutes from time, but Steve Cooper's men can now fully concentrate on their quest to gain promotion to the Premier League for the rest of the season.
Leicester were made to wait until the 94th minute to book their place in the last eight with a 1-0 win over Brighton.
Kelechi Iheanacho came off the bench to win the tie when the Nigerian headed home Youri Tielemans's cross from a quickly-taken corner.
Sheffield United also just needed a solitary goal to see off Bristol City 1-0 thanks to Billy Sharp's penalty after Alfie Mawson was sent off for handling David McGoldrick's goalbound shot.