Roberts deflected Gael Givet's 57th minute header past Wayne Hennessey to add to El-Hadji Diouf's first-half opener, then did all the hard work to tee up the third for David Dunn.
Things might have been different if Christophe Berra had not missed a fifth minute sitter for Wolves, who grabbed a consolation through substitute Stefan Maierhofer two minutes from time.
Diouf repaid Sam Allardyce's faith on his return to the line up when he took advantage of a blunder by Michael Mancienne, whose mis-timed challenge gave the Senegal man a clear run on goal.
Rovers almost grabbed a second in the 31st minute when Dunn ran at the defenders and laid the ball off to Wayne Andrews, whose shot was well blocked by Hennessey.
Wolves were consistently guilty of giving the ball away around their box and Morten Gamst Pedersen almost made them pay in the 44th minute but his free-kick struck a post.
Things briefly looked brighter for the visitors at the start of the second period as Maierhofer drove wide then almost got on the end of a lofted cross from Kevin Doyle.
But Rovers effectively sealed the points in the 57th minute when Givet met Dunn's corner with a powerful header, which might have been heading for Hennessey's hands had Roberts not got the slightest of touches.
Eight minutes later Roberts barged past the advancing Hennessey before stumbling and leaving Dunn to slot home Rovers' third.
Wolves did bag a consolation two minutes from time when Maierhofer controlled a corner from Matt Jarvis and poked home.