The Rovers boss will have heart surgery this week and was not at the game to see his team continue their Reebok hoodoo over his former club.
David Dunn's superb 32nd-minute opener and a Sam Ricketts own goal after half-time mean Wanderers have now not beaten their derby rivals at home in ten attempts.
Matt Taylor wasted a great chance to give the hosts the lead when he failed to convert Gavin McCann's cross on 13 minutes.
At the other end, Gael Givet headed over Jussi Jaaskelainen, but Gary Cahill got back to clear off the goal-line.
Taylor then saw his 30-yard free-kick deflect off Ryan Nelsen's outstretched leg and crash against the crossbar on 31 minutes.
And less than 60 seconds later Blackburn were ahead. Paul Robinson's long throw sent Franco di Santo sprinting away down the right. He picked out Jason Roberts, who played it into Dunn's path and the midfielder curled his shot beautifully into the top corner.
Taylor wasted another great opportunity on the stroke of half-time when he inexplicably headed over McCann's corner from two yards out.
El Hadji Diouf nearly came back to haunt his former club immediately after the restart, but McCann did superbly to head his volley off the line.
Blackburn surged forward in search of a second goal and Jaaskelainen denied di Santo before McCann was forced to clear off his own line again, this time from a Roberts header.
But Rovers went further ahead on 73 minutes when Ricketts headed Brett Emerton's crossfield ball into an empty net after Jaaskelainen had come rushing from his line in a dreadful mix-up.