Patrick Cutrone came off the bench to fire AC Milan
into the Coppa Italia quarter-finals on Saturday.
forward, who turned 21 at the start of the month, scored twice in extra time to help Milan win 2-0 at Sampdoria.
Milan, who lost last year's final to Juventus
, will face either Napoli or Sassuolo.
LAZIO VS NOVARA
Lazio eased into the quarter-finals with a crushing victory over third-division Novara.
Ciro Immobile scored twice as Lazio won 4-1 against one of the only two Serie C sides left.
The other, Virtus Entella, also travels to the Italian capital, to play Roma on Monday.
Milan and Sampdoria had their chances in regular time. Gonzalo Higuain even had the ball in the back of the net for Milan but it was ruled out for offside.
There was a frantic start to extra time and Milan goalkeeper Pepe Reina had to perform a double save to keep out Albin Ekdal's header and then to stop Dawid Kownacki's shot on the line.
Gennaro Gattuso brought on Cutrone at the start of extra time and he threw on Andrea Conti in the 99th minute.
Those two substitutes combined three minutes later to give Milan the lead as Cutrone volleyed in Conti's cross.
Cutrone all but sealed the result for Milan six minutes later when he dinked another volley over Sampdoria goalkeeper Rafael.