City were at their ruthless best in Belgium, scoring five on their way to victory in the group stage clash.
Guardiola's men were relentless, pressing Brugge high up the pitch, and it was a near perfect performance from the Spaniard's side, with a late goal from the hosts - after some sloppy defending - the only blot on an another stellar evening for City.
Agbonlahor spoke to Grealish after the game about his exhausting 90 minute outing, life at his new club and the way Guardiola has changed his game.
The talkSPORT pundit and former Aston Villa catpain also said there is a thing or two Manchester United could learn from their hard-working rivals.
Speaking on the talkSPORT Breakfast, Agbonlahor said: "If I was Ole in the hotel now, I'd be showing them the City game from last night.
"Look, they've got a a £100million player and all these superstars hunting the goalkeeper down, pressing all over the pitch, and leaving everything on the field.
"I spoke to Jack last night and he was shattered from the game.
"They are not just luxury players who can only do it when they've got the ball, they are pressing everyone and Manchester United should be doing that in every game they play."
Agbonlahor asked ex-Villa ace Grealish about playing under the great Guardiola, and the talkSPORT man revealed: "He said Pep is detailed in training, constant shape, you know exactly where you are meant to be, the positions you are meant to be and you can tell by the way they are playing. They're like robots.
"Rodri plays to De Bruyne, he's going to find Foden, and they play like they've got an extra man on the field.
"Last night I couldn't believe it. I felt sorry for the opposition."
Grealish moved to Man City for £100m from Aston Villa in the summer, leaving his boyhood club for the Premier League champions.
He has two goals and two assists so far in ten games played this season as he settles into his new surroundings.
Asked if being around and working with better players will make a difference for Grealish, Agbonlahor replied: "I think it's more that when you get the ball you are going to get it in the right positions. Someone is going to find the right pass.
"We've talked about Jack, but look at Cancelo's goal, Kyle Walker's goal - you can make these crazy runs from unnatural positions for a full back and still get found by quality players.
"That's the difference now with Jack, he's playing with England and Man City with quality players and you know you are always going to get chances."