Sergio Conceicao's side were on the defensive for long periods at the Estadio do Dragao, but a series of superb saves from Porto keeper Agustin Marchesin...
City are off to their worst league start since the first few months of the club's Abu Dhabi-backed ownership as Guardiola's men sit 12th.
Four straight wins have taken Spurs to 20 points after nine games, ahead of Liverpool on goal difference, but Frank Lampard's Chelsea are just two points...
Barcelona, Juventus, Chelsea and Sevilla punched their tickets to the knockout phase on Tuesday.
City's board showed how fully they remain committed to the Guardiola project by extending his contract to 2023 last week.
Victory moved Tottenham moved two points ahead of Chelsea, who they face next weekend at Stamford Bridge.
Guardiola has won six major trophies in his first four seasons in Manchester, including back-to-back Premier League titles in 2017/18 and 2018/19.
Guardiola was due to be out of contract at the end of this season and it had been suggested the Spaniard might be ready to leave City.
Liverpool manager Klopp and Manchester City boss Guardiola have been vociferous in their calls for the Premier League to allow five substitutions
Paul Pogba remains a square peg in a round hole at Manchester United despite occasional flashes of brilliance.
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