© Getty Images
Gervinho had an early opportunity to fire the Gillorossi ahead after meeting a cross inside the box, but he failed to find the target after working some space inside the area.
Nainggolan did give the visitors the lead on 26 minutes, however, when he reacted quickly to get in front of Neto and fired a close-range shot into the back of the net.
Francesco Totti almost doubled his side's advantage shortly before the interval, but he shot the ball wide of the target after pouncing on a rebound on the edge of the box.
Stefan Savic had an opportunity to pull Fiorentina level when he won the ball following a set piece, only for his shot from inside the area to sail narrowly over the crossbar.
Roma went into the closing stages holding onto their slender lead, but Alessandro Matri almost made certain of the points when he struck the ball towards goal from inside the area, only for his effort to be blocked.
It was not to matter, though, with the referee signalling for full time shortly after, ensuring Roma strengthen their grip on second place in the Serie A table.