The 18-year-old – who has been training with the first team squad for the past three months - produced a mature, assured display on his first start and was unlucky to mark the occasion with a goal.
Manager Pep Guardiola was full of praise for the attacking midfielder’s display and humble attitude afterwards.
And Palmer – who has been at City since he was a small boy – admitted it was a special moment he would never forget.
“Obviously, it's is a dream come true to be at the Club I’ve been at since the age of six and make my debut and I’m glad we’re in the next round,” he reflected.
“(My outstanding memory was) Probably in the meeting before when the boss told me I was starting. I was just dead excited and couldn't wait to play.
“It’s mad being mad out there. They are the best players in the world and as a young kid coming through it’s a dream to play with players like that.
“The difference is the speed of it and every day on the training ground everyone is it at. It’s tremendous.”
Palmer played the full 90 minutes and, on another day, could have scored at least once though he opted to be unselfish on at least two occasions and looked to pass when he could have gone for goal.
“I thought it (the second chance) was a tight angle and Raheem was on his hat-trick so I thought I’d square it,” Cole revealed.
And the Wythenshawe-born youngster also revealed that his match shirt was already earmarked for a special destination.
“No this one isn’t going anywhere. It’s going in a frame and to my mum and dad at home!”