Slaven Bilic called Charlie Austin 'pure class' as the striker came off the bench to fire Albion to a 3-2 victory at neighbours Birmingham City.
Bilic's side were heading for a second defeat of the season until he changed formation and brought on Austin with just 20 minutes to go.
The change worked almost immediately with Austin taking just two minutes to fire in a wonderful equaliser before his late header saw the Baggies take all three points.
"Charlie Austin's first goal was pure class. His second goal was class, too. His movement, the way he got rid of the defender. It's great to have that kind of player," said Bilic.
"It was a proper derby, lots of effort, lots of tackles, and we had a bit more quality. But we conceded from two set-pieces. We can't be happy with that.
"In derbies, it can be hard to stay calm, but we did that and it comes from the belief and confidence we have got from recent games."