They started as they meant to go on, passing the ball in typical style in midfield, and they opened the scoring with the first shot on target.
Just seven minutes in, Youssouf Mulumbu drove forwards and fired in from 25 yards, with Karl Darlow unable to keep it out.
James Morrison looked a threat all half but West Brom's second came from the spot after 17 minutes, Shane Long converting after he was fouled.
It remained comfortable for West Brom for the remainder of the half, although they were unable to add to their lead.
Forest were better at the start of the second half and managed a few shots on goal, but West Brom were solid at the back, quick on the break and too strong in midfield.
The inevitable substitutions broke up the flow of the game and apart from a disallowed goal for the visitors there was little danger of any more action as the two sides played out the result.