Albion lost their first game of the season 2-1 at Ewood Park after goals in a six-minute spell either side of half time from the hosts.
Steve Bruce named an unchanged XI to the side which had done well against Watford earlier in the week.
However, the Baggies struggled to create any clear openings in front of goal and it was Blackburn who opened the scoring in the 41st minute when the dangerous Ben Bereton-Diaz curled home from the edge of area.
Blackburn pushed for a second after the break and Darnell Furlong was caught out of position with Bereton-Diaz enjoying the space to cross for the unmarked Sam Gallagher to add a second just two minutes into the second half.
Albion tried to regroup and got a goalback on the hour mark when Grady Diangana's shot was deflected into the net to the give the visitors hope.
Karlon Grant then wasted an excellent opportunity to equalise when he fired straigtht at the keeper as the Baggies were unable to maintain their unbeaten start to the season.