Hearts U20s suffered their first league defeat of the season as they lost 3-0 to St Mirren on Tuesday night.
Andy Kirk included Ashley Smith-Brown and Cole Stockton in his starting eleven at the Paisley 2021 Stadium but it was the hosts who took command early on.
Jordan Kirkpatrick fired in a free-kick on six minutes to give the hosts the lead and the Buddies went into the interval 1-0 up.
Ross Stewart then volleyed home to make it 2-0 in the second half before Conor O'Keefe made it 3-0 ten minutes later.
The Wee Jambos are next in action this coming Monday when they host Celtic at Ochilview.