Draw with Liverpool delights Guardiola
In an enthralling encounter, both sides threw caution to the wind to attack rather than defend and despite gilt-edge chances for Raheem Sterling and David Silva for the hosts, the match remained goalless at the break.
The deadlock was broken six minutes after the restart when James Milner scored from the penalty spot following Gael Clichy's clumsy challenge on Sadio Mane.
But Sergio Aguero denied Liverpool all three points when he swept in Kevin De Bruyne's inviting cross to level on 69 minutes before Adam Lallana and Aguero missed glorious chances at opposite ends to steal victory.
The Spaniard told Sky Sports: "You cannot imagine. This is one of the happiest days of my career as a manager.
"After our defeat in the Champions League, for two days we were so, so sad and in the training sessions we didn't talk too much.
"We arrive here against Liverpool, who haven't had European football all year and had all week to prepare for that game, and how we fight and how we run and how we showed spirit - today is one of the happiest days of my life as a manager.