West Brom took an undeserved lead through Simon Brown’s first half strike, but a strong Rovers side always looked threatening and Nils Eric Johannson levelled terms with a precise header.
Jansen has been dropped from Graeme Souness’ starting line up recently, in favour of youngster Paul Gallagher and Dwight Yorke, but this performance will be the ultimate response to the Blackburn boss.
The fans favourite Jansen, turned neatly following a throw-in and lashed the ball home to seal the win for the reserves just 3 minutes from time.
Rovers Reserves: Enckelman, Taylor Michael, McEveley, Danns, Taylor Martin, Johansson, Watt, Donnelly, Johnson (Grabbi 70), Jansen, Harkins (Morgan 60)
Subs not used: Renton, Corvino, Weaver, Bruce.