Garna was introduced in the 59th minute, with the sides locked at 0-0, and drove in from the right-hand side before inching a left-footed effort beyond Ederson, sending the United fans behind the goal into jubilant celebrations.
Unfortunately for our players and supporters, Bernardo Silva levelled for City late on, before we were edged in a topsy-turvy penalty shootout.
You can watch Garnacho's finish, courtesy of ITV, below.
Alejandro Garnacho brilliantly gives Man Utd the lead ud83eudd29
Could that be the winner for Erik ten Hag's side...? ud83dudc40#ITVFootball | #CommunityShield pic.