"That means a lot in this toughest period, in the Christmas and winter time," said Guardiola, whose side leads the Premier League by five points with a game in hand. "To do what we have done in this time is quite remarkable."
City took the lead in the 30th minute when Kyle Walker's low cross into the penalty area was missed by the sliding Ferran Torres at the near post and ended up creeping inside the far post.
Rodri played in Raheem Sterling to double the advantage in the 47th, before Gabriel Jesus controlled a header across goal by Bernardo Silva and slammed in a left-footed shot three minutes later. Morgan Whittaker grabbed a consolation for Swansea
City won 20 straight games in all competitions from August-December 2017, also under Guardiola, but one of those victories came in a penalty shootout in the League Cup after a 0-0 draw after extra time.
Guardiola earned his 200th win in 268 games in charge of City. However, it was a historic night for very different reasons for his long-time coaching rival, Jose Mourinho.
For just the third time in a managerial career spanning nearly 1000 games, Mourinho saw one of his teams concede five goals in a game as Tottenham lost a thriller at Goodison Park.
Bernard netted the winning goal in the 97th minute for Everton, who trailed after three minutes, scored three goals in seven minutes near the end of the first half to forge ahead, then conceded a goal to Harry Kane with seven minutes left of regulation time to be taken to extra time.
The only other times a team managed by Mourinho conceded five goals in a match were when Real Madrid were thrashed 5-0 by Barcelona and Chelsea were beaten 5-3 at Tottenham.
"It was the mouse and the cat," the Portuguese coach said after the thriller at Goodison Park. "The mouse was our defensive mistakes and the cat was us trying to compensate for us playing very well, scoring goals but it was not enough."
Kane came off the bench to make it 4-4 with his 209th goal for Tottenham in 318 appearances, taking him past Bobby Smith to become second-highest scorer in Spurs' history behind Jimmy Greaves (266 in 379).
Everton reached the quarter-finals for the first time since 2016. Also advancing to the last eight were Sheffield United, a 1-0 winner against second-tier Bristol City, and Leicester, who beat Brighton by the same score thanks to Kelechi Iheanacho's goal in the fourth minute of stoppage time.
- AP