Manchester City's UEFA Youth League hopes suffered a blow, as they fell to a second defeat in the group stage, falling to a 1-0 reverse to Atalanta.
A solitary first half Roberto Piccoli penalty clinched all three points in Matchday Four at the Bortolotti Sport Centre, condemning the visitors to back-to-back losses against the Italians.
The defeat leaves City in third place with two games remaining in Group C.
Atalanta's victory lifts the Italian side three points above Harsley's charges, while Dinamo Zagreb sit top with eight points from four games.