Guardiola admits Man City drank 'all the alcohol in Manchester' prior to Brighton draw
For the first time since February, City dropped league points as a stunning goal by Brighton's Paraguayan teenager Julio Enciso snapped their 12-game winning run in the league.
Erling Haaland, who set up Phil Foden's opener, had a late goal disallowed, resulting in a yellow card for Guardiola.
City have one more league game left before an FA Cup final against Manchester United and a Champions League final against Inter Milan. Victories in both will see them match Man Utd's treble, so Guardiola's side might have been excused for taking their foot off the gas having won a fifth title in six seasons at the weekend.
That they did not win, however, was more to do with an excellent Brighton side who sealed a Europa League spot, says the Spaniard, who was pleased with his side's effort given they'd been celebrating heavily two days prior.
"Exceptional game. Congratulations to Brighton for their deserved qualification to the Europa League," Guardiola told Sky Sports.
"The game we played, 48 hours after we drank all the alcohol in Manchester, 48 hours later we behaved and we showed why we were the champions against that team.
"We showed what we have done with and without the ball. I didn't see one drop in our intensity and idea. They had chances, we had chances, we scored a goal, they scored a goal.
"Both teams want the ball, both teams want to press. The keepers are fundamental in this game. The quality (Brighton) have, they are an exceptional team."
Guardiola shared some jokes during the game with Brighton boss Roberto De Zerbi and warmly congratulated the home players, but he was angry that Haaland's goal was disallowed for shirt-pulling.
"Watch it. Watch it, if it's a fault, every action for Erling is a fault," he said of his 52-goal striker.
The manager said his side cannot afford to lose any momentum as they seek to make history.
"I didn't see it, against Chelsea I didn't see it today. During the week we have to rest, recover mentally," he said.
"It's been demanding for the past six months playing Bayern Munich, Real Madrid, chasing Arsenal. The training now is just relaxed."
Brighton's point means they can make plans for the Europa League, the club's first European venture.
"What an achievement, what a club, what a group of guys. The togetherness, the culture and we are driven in by a top, top manager. Special times," keeper Jason Steele said.