Montella off to winning start with Roma
Former Roma youth-team coach and striker Montella has taken over until the end of the season after Claudio Ranieri's resignation on Sunday following four straight defeats.
De Rossi stopped the rot and sent Roma up to sixth after Mirko Vucinic picked up a loose ball in the area and played it back for the Italy midfielder to score.
Montella left former strike partner Francesco Totti on the bench but the club captain, who had a strained relationship with Ranieri because of a number of substitute appearances, came on in the second half.
The game, originally postponed after 16 minutes last month because of snow, kicked off with 16 minutes already on the clock as is the tradition in Italy.