'Rusty' Phil Foden happy to jump start Man City season in Bratislava rout
The scoreline did little justice to the visitors' dominance as Ilkay Gundogan and Foden struck within the first 15 minutes to set City on their way in the Slovak capital.
Erling Haaland added his 42nd Champions League goal in 41 appearances before James McAtee registered his first goal for the club.
After a stuttering start to their European campaign in a 0-0 draw at home to Inter Milan on matchday one, the English champions are up and running in the competition's new format.
Foden has been bedded back into action gently by Guardiola after his exertions in England's run to the Euro 2024 final and illness in the opening weeks of the season.
The 24-year-old's stellar performances saw him earn Premier League player of the year awards last season and his return to form is a timely boost with Kevin De Bruyne and Rodri ruled out by injury.
"I had more chances to score, on another night it could've been more - but we're delighted to win 4-0. It's been a slow start to the season for me, so it was nice to get back out there and score," Foden told TNT Sports.
"Very happy with the performance, I know there’s still things I can work on and get better. I’m still a little bit rusty."
Slovan had already suffered a baptism of fire in a 5-1 thrashing at Celtic in their opening match and were given another lesson by the 2023 winners.
Bratislava boss Vladimir Weiss had compared City manager Pep Guardiola's "genius" to that of Catalan architect and designer Antoni Gaudi on the eve of the game.
Six changes
But Guardiola did not need to be at his creative best to draw up a winning game plan as the gulf between the sides was clear from the opening seconds.
Guardiola could even afford the luxury of making six changes from the side that drew 1-1 at Newcastle on Saturday.
Gundogan opened the floodgates with his first goal since returning from Barcelona.
The City captain for the night's powerful shot from the edge of the area deflected into the top corner.
Foden curled home City's second into the bottom corner with customary precision on 15 minutes.
"He's still not at his best, but make a fantastic goal, had more chances and step-by-step he is coming back," said Guardiola.
"We had to do our job and we did it. Lots of chances and first three points of the competition."
The visitors should have been further in front even before half-time as a combination of good fortune and the woodwork kept the score down.
Jeremy Doku curled an effort onto the crossbar before Foden's low shot was turned onto the post by Bratislava goalkeeper Dominik Takac.
Gundogan then became the third City player denied as another powerful strike from the German came back off the bar.
The one thing missing from City's dominant first half display was a Haaland goal.
It duly arrived on 58 minutes as the Norwegian easily raced onto Rico Lewis' pass and rounded the 'keeper before tapping in his 11th goal in eight games this season.
Guardiola was able to give Haaland a rare rest for the closing stages but City still added to their lead.
Foden's inventive through ball was given the finish it deserved from McAtee.