Alphadjo Cissè scored a hat trick as AC Milan got their Europa League campaign up and running with a 4-0 win at RB Salzburg, who slipped to a first defeat of the season.

The Rossoneri -- beaten 2-0 by Benfica at San Siro in their opening match of the league stage -- took an early lead through Cissè's header.

The 19-year-old knocked in another just before the break and then completed his treble with a close-range finish four minutes into the second half.

Substitute Gonçalo Ramos added a late fourth before AC Milan finished with 10 men when Filippo Terracciano was sent off with seven minutes left for pushing over Dominik Schmid.

Cissè broke the deadlock after 15 minutes when he glanced in a floated cross from on-loan Nottingham Forest winger Omari Hutchinson, one of several changes to the side by AC Milan boss Ruben Amorim.

Salzburg -- who had been on a 15-match unbeaten run through all competitions this season under new head coach Danny Rohl -- thought they had an equalizer in the 23rd minute when Haris Tabakovic tapped home a cross from Leandro Morgalla, but the ball had rolled out of play.

Cissè scored again in the 32nd minute when he knocked in a cushioned ball back from Davide Bartesaghi after a fine angled pass through the penalty area by Adrien Rabiot.

The Frenchman then set up Cissè's hat trick after a break down the left and low cross into the six-yard box, with the teenager ruled just onside following a lengthy VAR review.

Ramos made it 4-0 with 18 minutes left after Ardon Jashari had taken the ball off Salzburg midfielder Bartosz Mazurek as he looked to play out from the back.

Salzburg substitute Gaoussou Diakité flashed his shot wide before Terracciano saw red after pushing over Schmid just outside the penalty area as he ran clear following a swift counter attack.