FA Cup: West Brom sneak past Peterborough on penalties
The EPL side progressed to the fifth round of the competition.
The game finished 1-1 after extra time, Peterborough taking the lead having dominated the first half when winger Jon Taylor found space to slot home from 15 metres after 55 minutes.
Midfielder Darren Fletcher grabbed West Brom's equaliser with a crisp half-volley from the edge of the penalty area.
Lee Angol missed the decisive spot-kick in the shootout for Peterborough and West Brom will travel to championship side Reading in the fifth round of the competition.