The 18-year-old, who signed a new long-term contract with the Club earlier in the week, was named in the starting line-up and came close to a spectacular second half goal, seeing a superb volley being tipped over the bar.
Two goals from Leroy Sane helped the Blues come from behind to claim the victory in what was an entertaining game.
And as he reflected on the victory and looked ahead to the knockout stages, the City boss was effusive in his praise for the Stockport-born midfielder.
“Second half, the team was much better. Not just Phil but in general over 90 minutes, and Phil was outstanding,” said Guardiola.
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“I never had doubts. The quality he has with the ball… he looks skinny, but he is really strong.
“He is a huge talent. England has a diamond.
“It’s not easy to play in the big clubs, to play with David (Silva), Kevin (De Bruyne), Bernardo (Silva). He is incredible.
“In training sessions every day... He has had minutes and will have in the future.
“Against German teams, it is so demanding, but he played like a man.”
The City manager also expressed his delight at City’s progress in the competition.
Especially given the way several other top sides have failed to progress through to the knockout stages.
“The quality in Europe is so high. The teams are so good, the managers are good,” Guardiola added.
“The best teams in Europe are here. That’s normal. It’s more difficult because opponents have more quality. Football depends on quality.
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“What’s really important is the quality of players and in Europe, everybody has good players.
“Many top teams are out, like Inter Milan, Napoli. I am so glad to be in the last 16. It’s an incredible success for any team to go through.
“It’s so demanding. We will try to arrive in February in a good condition.”