Micah Hamilton said he had been left struggling for words following his goalscoring debut for Manchester City in the Champions League.

Once a ball-boy with the English giants, the 20-year-old seized his chance after manager Pep Guardiola made several changes to the team for Wednesday's concluding 'dead' group-stage match away to Red Star Belgrade.

Hamilton opened the scoring in the first half with a fine strike and also secured a late penalty as holders City won 3-2 to end Group G with six wins from six.

"I don't even know what to say," City academy graduate Hamilton told the club's website.

"I started just trying to ease into the game and then the moment came and I just took the opportunity. I didn't know what to do to celebrate!

"It's not even sunk in yet. I'm just taking it all in. It's amazing."

Manchester-born Hamilton joined City at the age of nine.

Injuries delayed his entry into the first team but Hamilton showed his class in Belgrade alongside fellow academy 'graduates' Rico Lewis and Oscar Bobb, the scorer of City's second goal.

"I've played with (Rico) right through the age groups and now to be doing it on the big stage is something mad," said Hamilton.

"And the same with Oscar.

"Two top players. To have them there by my side felt so good.

"The academy system is top at City and especially when you train with the first team day to day, you improve every day. They make you feel comfortable and welcome and I just felt myself on the pitch.

"I'm just going to keep my head down, keep working and hopefully chances will come."

Hamilton and Bobb gave City a 2-0 lead before Hwang In-beom pulled a goal back for Red Star.

Kalvin Phillips, making a rare start, restored City's two-goal advantage with an 85th-minute penalty before Aleksandar Katai headed in a late consolation for the hosts.

This was Phillips' first goal for City since his move from Leeds last year.

There has been speculation the England midfielder could leave during the January transfer window, with Guardiola saying: "I don't know what is going to happen. Now he is here. There are a lot of games until the end of January, hopefully he can help us."