Sassuolo's 4-3 triumph over the seven-time European champions last Sunday ended a run of five successive defeats in league and cup but, rather than heralding a revival, it proved a false dawn as they slumped to another loss on Sunday.
Immobile opened the scoring in the 25th minute and Brighi added a second just after the break as Torino remained in seventh place in the standings while leaving Sassuolo stuck in the bottom three.
That victory over Milan would have given Sassuolo a huge confidence boost and they began the better on Sunday with Jasmin Kurtic being denied by visiting goalkeeper Daniele Padelli before Raman Chibsah headed an Alessandro Longhi cross wide.
However, that bright start came to an end as they were hit by a clinical breakaway goal by Immobile, who stole possession on the halfway line, raced towards the area and then coolly dinked the ball over home keeper Gianluca Pegolo.
The hosts tried to respond before the break with efforts from Thomas Manfredini, Francesco Magnanelli and Domenico Berardi - the four-goal hero against Milan - but none of them were on target.
Berardi also tried his luck immediately after the restart but his shot went narrowly over, and within two minutes of that chance Torino had doubled their lead and Sassuolo were heading towards an 11th defeat of the campaign.
Pegolo got his finger tips to Alessio Cerci's curling shot from the right-hand side of the area but he could not get enough on the ball to take it away from danger, and Brighi slid in at the far post to turn the ball home.
Again Sassuolo attempted to fight back but the closest they came to getting on the scoresheet was Reto Ziegler's shot that was saved by Padelli.