Stephane Sessegnon hit back at Paolo Di Canio with a debut goal for West Brom to push former club Sunderland to another defeat as they were beaten 3-0.
Sessegnon, who joined the Baggies in an acrimonious deadline day move from Wearside earlier this month, struck after 20 minutes as Sunderland lost at The Hawthorns to remain bottom of the Barclays Premier League.
Liam Ridgewell secured victory with a second goal 14 minutes from time before another impressive new signing in Morgan Amalfitano added a third in injury time.
It proved a dismal afternoon for the Black Cats, who only had 10 men for the closing 15 minutes after Steven Fletcher was forced off injured with all substitutes having been used.
The result is sure to pile the pressure on Sunderland manager Di Canio, who made the controversial decision to sell the popular Sessegnon.
There was clear irritation among the visiting fans after the final whistle was blown but Di Canio approached them to applaud and gesticulated they should keep their chins up.
Yet while his side have just one point, opposite number Steve Clarke could breathe a sigh of relief after finally securing a first win.
Sessegnon, whose debut had been delayed by red tape, did the business for him in an impressive first appearance.
His name was read out to loud cheers from both sets of supporters prior to the match and, perhaps inevitably, he needed little time to make his mark.
He was in the right place to tuck home the opening goal after the hosts had broken down the right in the 20th minute.