Atalanta's Teun Koopmeiners scores their second goal from the penalty spot past AC Milan's Mike Maignan [Source: Reuters]

Teun Koopmeiners scored twice as Atalanta came back from a goal down to beat AC Milan 2-1 at the San Siro in their Coppa Italia quarter-final.

Rafael Leao broke the deadlock for Milan just before halftime with an elegant first-time finish from Theo Hernandez’s pass, but three minutes later an unmarked Koopmeiners received a ball from Emil Holm before guiding a shot into the far corner.

Koopmeiners completed the comeback for Atalanta in the 59th minute when he converted a penalty after Alex Jimenez fouled Aleksei Miranchuk.

Atalanta manager Gian Piero Gasperini was sent off late in the first half after a heated conversation with the referee that persisted despite an initial warning.

Under Gasperini, Atalanta have reached the Coppa semi-finals four times.

The closing minutes intensified as a desperate Milan threw everything forward, but Atalanta keeper Marco Carnesecchi stopped attempts from Christian Pulisic and Yunus Musah.

In the dying seconds, Milan’s hopes were raised as an alleged handball by Miranchuk inside the box underwent a VAR-check but it was dismissed.

Milan’s back-up goalkeeper Antonio Mirante received a direct red card from the bench for dissent following his protest against the decision.

Atalanta will play Fiorentina in a two-legged semi-final in April following Vincenzo Italiano’s side’s win over Bologna on penalties on Tuesday.