Roma stretched their unbeaten run to seven matches in all competitions with a comfortable 2-0 win over Fiorentina at the Stadio Olimpico on Sunday.
The result moves the capital club into seventh place on 11 points, but Fiorentina are stranded in 11th with just one win in their last five Serie A matches.
The visitors enjoyed an encouraging opening two minutes as Gaetano Castrovilli curled a shot wide before zipping a dangerous ball across the area that required an alert clearance.
But that proved to be as good as it got for La Viola, and they went behind after 12 minutes when a long kick by Antonio Mirante sailed over the defence for Spinazzola to sprint through and slide a finish into the bottom corner.
Roma were soon on top and pushing for a second, but Fiorentina goalkeeper Bartlomiej Dragowski was determined to thwart them as he pushed an Edin Dzeko header over before performing a superb double save to deny strikes from Rick Karsdorp and Henrikh Mkhitaryan.
It was dismal performance from the visitors, and things were made even worse when Lucas Martinez Quarta, making just his second Serie A appearance for the Viola, earned a straight red card for a reckless lunge at Dzeko.