Blackpool's Scottish captain Charlie Adam duly slotted home the penalty much to the delight of the Tangerines' fans who were hoping to witness their first ever home top-flight victory since 1971.
Things went from bad to worse on the half hour mark as Chilean defender Gonzalo Jara horrifically lunged towards Luke Varney by the corner flag. Referee Oliver once again brought out his red card and Roberto Di Matteo's men were left with an up hill task down to nine men in the pouring rain.
West Brom's players held firm and put in a spirited display looking more than equal to Blackpool at times but their resolve finally fell when Luke Varney finished from close range after Elliot Grandin's cross.
West Brom could have earned a point in the 90th minute but Irish star Steven Reid hit his effort from 8-yards over the bar. The result means Di Matteo's men remain in fifth position while Blackpool now find themselves in ninth place after ten games in their maiden Premier League season.