Guardiola had been worried his side’s performance level would drop against Brighton.
Guardiola feared his riding side could be suffering from a hangover in Sussex after the weekend’s title celebrations.
But the Spaniard was pleasantly surprised by the performance of his players during the enthralling match on the south coast.
Phil Foden fired City ahead at the Amex Stadium before Julio Enciso’s stunning equalizer sealed Albion’s sixth-placed place in next season’s Europa League.
Erling Haaland was denied a late winner after VAR spotted his shirt being pulled by Seagulls defender Levi Colwill.
“I was a bit worried about how much we’d drop our (level) with what we’ve been doing for the last four, five, six months,” Guardiola said.
“Forty hours (before) we drank all the alcohol in Manchester and the way they played was excellent.
“I enjoyed it a lot, especially when I was the champion.
“You have to come here to win the game, we know it’s going to be tough. They’re a fantastic team in all departments, that’s why they’re in the Europa League, deservedly so.
“And we also showed why we are the best team in England.
Guardiola had a relatively early night after the trophy presentation, which followed Sunday’s 1-0 win over Chelsea, while City’s players spent the next day recovering in the saunas.
“I was in bed with my wife at 10.30pm, I was exhausted,” he said.
“I watched the match of the day and I slept like a baby, but I know the players did what they had to do.
“When you win the Premier League you have to celebrate. They did it with their families, they enjoyed it a lot and the next morning was just sauna.
“And the day after that we had a bit of a chat in the afternoon, ‘Boys, we’ve got to be ready for Brighton’ and they did it.
City, who capped a winning campaign in the top flight at Brentford on Sunday, were given a guard of honor by their hosts before kick-off.
Foden opened the scoring in the 25th minute with his fifth goal in as many starts against the Seagulls before Enciso’s spectacular finish halted City’s 12-game winning streak in the top flight.
Guardiola believes this high-level competition will be crucial preparation for the upcoming FA Cup final against Manchester United, followed by a Champions League clash with Inter Milan in Istanbul.
“We need these opponents to give us their best,” he said. “This is so important. Brentford will be the same.
“It’s really, really good, the teams help us to keep this level because the finals you have to play at this level otherwise it’s going to be so difficult.”
Guardiola was hopeful about the knocks that forced Foden and John Stones off, while also confirming that those absent – Nathan Ake, Ruben Dias, Aymeric Laporte, Manuel Akanji and Jack Grealish – have injury problems.
The thrilling encounter was a fitting final home game to a memorable campaign for record-breaking Brighton and saw off a remote chance of slipping into the Europa Conference League on the final day at seventh-placed Aston Villa.
Seagulls head coach Roberto De Zerbi said: “I’m happy because we have to respect our club, our fans, but we have to show courage, show we believe in ourselves to win against the best team in the world.
“We needed one point. we didn’t get the gift. We deserved a point today.
“I’m really proud because I think today was one of the best games this season.”
“It was very difficult, but we played with incredible quality. We deserve to play in the Europa League for our mentality.”