Daniele De Rossi's Roma won their first local derby in more than two years and made sure of fifth spot in Italy's top flight for another week, ahead of Atalanta who have another game in hand.
Serie A is leading the race for an extra spot in next year's Champions League meaning a top-five finish could be enough for Roma to qualify for Europe's leading club competition for the first time since 2018.
Gianluca Mancini ensured Roma would have bragging rights in the capital city with a bullet header three minutes before half-time at the Stadio Olimpico. Italy defender Mancini thumped home his fifth goal of the season from Paulo Dybala's corner to give Roma a deserved win.
Former Roma captain De Rossi won his first Rome derby as coach at the first attempt after four without a win under his predecessor Jose Mourinho.