The victory at the Gewiss Stadium on Sunday evening also put a five-point gap between themselves and the Biancocelesti, as Mario Pasalic opened the scoring, De Ketelaere netted a brace and Ciro Immobile found a late consolation goal from the penalty spot.
De Ketelaere thriving away from AC Milan
After a difficult debut season in Serie A with AC Milan, the Rossoneri allowed the 22-year-old to make the short journey across to Bergamo in the summer, probably hoping more than expecting the former Club Brugge attacker to shine under Nerazzurri coach Gian Piero Gasperini.
De Ketelaere has looked a different player under the tutelage of the veteran tactician and played a part in all three goals against the Romans. The Belgium international sending over the cross that was headed down to Pasalic to score the first on 16 minutes.