The midfielder, who had two spells on loan at the Pittodrie club prior to this season, scored what proved to be the victor with a shot in added time at the end of the first half.
"I will repeat, when I came in he wasn't ready to play week by week, but we could see that there was a talent there".
The Croatian striker, who is now playing in China, was a fans' favourite as he helped Rangers win the League Cup and SPL title in 2010/11, and in a rare one-to-one he discusses the mixed emotions he had when he left Ibrox for Everton's Goodison Park.
Hoops midfielder Tom Rogic struck the outside of the post in the seventh minute with a left-footed snap-shot from 25 yards before James Forrest's attempt with the outside of his right foot escaped keeper Lewis' right-hand post by a yard.
Celtic will look to build on their Betfred Cup success at the weekend when they return to Scottish Premiership action to take on Motherwell at Fir Park on Wednesday evening, but they will be missing a key defender for the clash, according to Sky Sports.
However, the Dons manager was unhappy with referee Andrew Dallas's decision to award Celtic a penalty when Dominic Ball's headed clearance came off his arm, which appeared accidental and outside the box to boot.
He said: "It wasn't a penalty in the first place and, if we don't have a goalkeeper like Joe Lewis, it could be 2-0 and far more hard". The striker drove well at the Celtic defence but Craig Gordon saved well.
Defender Jozo Simunovic replaced Boyata on the hour-mark and immediately his attempted clearance smacked off his own crossbar.
"I won't sleep very well tonight", he said.
He said: "Thankfully he was okay, he is sitting up in hospital, he is getting tests done".
"Ryan went away and got that physicality in terms of body strength and durability".
He said: 'It wasn't a penalty and I also felt there was another yellow challenge from Christie, on the halfway line.