From the moment he emerged from the tunnel, turning left to the away dugout as opposed to his right as he had done most weeks since 2013, Guardiola was a coiled spring of intensity, studying and watching all that was unfolding in front of him before bursting into life.
He might have been in an environment that was all so familiar but the brisk manner in which he scuttled past the army of photographers who were waiting for him, gripping on to a bottle of water, showed Guardiola was not interested in sentiment.
There was one brief personal touch, as he gave a wave and a smile to the children who had gathered behind his dugout, but as soon as the game began, it was total focus.
Within 50 seconds, he was out of his seat, prowling his technical area and bellowing instructions to Aleksander Kolarov.
Possession is Guardiola's mantra. Though the term 'tiki-taka' might be the one with which he is synonymous, Guardiola does not want to see his teams play pointless passes in areas where they cannot do damage, he wants them to be aggressive and get the ball forward quickly.
Giving the ball away cheaply, however, enrages him and the first City player to feel his wrath for one such slip was 18-year-old defender Tosin Adarabioyo, who – in the 14th minute – put a crossfield ball out of play.
On the touchline, Guardiola shook his head and then put his hands over his face before turning around to look at his coaching team in exasperation. For the remainder of the first half, Adarabioyo – born in Manchester – must have felt like he was receiving running commentary from his manager.
Bayern, with stars such as Philipp Lahm, Javi Martinez and Xabi Alonso in their starting line-up, looked fitter, sharper and slicker but, then again, that was only to be expected given the makeshift nature of the team Guardiola started.
The hosts could have been out of sight by half-time and it was only down to Willy Caballero that City were able to go into the interval all square. His first stop from David Alaba in the 17th minute was excellent, the two that followed from Julian Green in the 35th and 42nd minutes were even better.
Bayern prepared a special 'Welcome back!' banner for their former manager as he headed back to the Allianz Arena with his new club
New Bayern manager Ancelotti shared a pre-match embrace with his predecessor ahead of the first game of both of their new reigns
Guardiola, in casual wear for his first friendly as City manager, was on his feet on the touchline almost immediately to encourage his team
City midfielder Fernandinho, captaining the side for Guardiola's first game, chases down Bayern winger Franck Ribery in the early stages
Youngster Tosin Adarabioyo gets the better of Ribery during an early aerial challenge with the experienced French playmaker
Ribery was the centre of attention early on and his shirt was seen to be ripped apart across the back after 13 minutes of the game
Bayern's American forward Julian Green, deputising for absent senior colleagues in attack, shields the ball from City's Pablo Maffeo
City's Spanish winger Jesus Navas struggled to find a way past Bayern centre back Javi Martinez at the Allianz Arena
Former Liverpool midfielder Xabi Alonso gets the better of Fernandinho as both sides are put through their paces in Munich
Caballero, the No 2 keeper, did himself no harm with this performance nor did Oleksandr Zinchenko, one of a number of new signings to have arrived at City since Guardiola was appointed. The Ukraine international was bright in the 45 minutes he played and had City's best chance.
A succession of substitutes in the second half disrupted the flow of the game and the tempo inevitably dipped late on, given the baking temperatures and the stage we are at in preparations for the new campaign.
Still, there was time for Bayern to score the only goal through Erdal Ozturk in the 76th minute, his shot beating Angus Gunn who had replaced Caballero, with the aid of slight deflection off Gael Clichy. Guardiola simply turned on his heels and went back to his seat for a moment.
But it wasn't long before he was back, barking, gesticulating and studying. Guardiola, you see, finds it difficult to settle. That is what happens when you a searching for football perfection.
Guardiola looked full of thought as his team headed for the tunnel at half-time having held a more-experienced Bayern side back
Former Arsenal midfielder Mikel Arteta, sitting on the bench for the first time as City's new co-assistant coach, offered up his analysis
Guardiola controlled a ball that came his way on the touchline at the stadium he used to call his home during his time at Bayern
Juan Bernat keeps marker Pablo Maffeo at arm's length close to the corner flag with City's pressing game forcing Bayern away from goal
Sinan Bytyqi looks to lead City forward with the ball at his feet after replacing Aleksandar Kolarov in the 66th minute at the Allianz Arena
Ozturk wheels away to celebrate after finding the net with his effort from range fortunate to be deflected into the corner of the net
Ozturk looked delighted after scoring the only goal of the game in the 76th minute of the clash between the German and English giants