David Moyes' side remain bottom of the Premier League due to the loss at the Hawthorns, which saw the hosts tighten their grip on the top half
Darren Fletcher and Chris Brunt inflicted more misery on rock bottom Sunderland as West Brom got back to winning ways with a 2-0 Premier League victory on Saturday.
Sunderland slipped to the foot of the table after Swansea City's win over Liverpool and they failed to provide any sign of climbing out of the relegation zone at The Hawthorns.
Instead it was Albion who dominated and eventually opened the scoring through captain Darren Fletcher, his fourth for the club - all of which have come at home.
It did not take long for that advantage to be doubled as Brunt profited from some woeful Sunderland defending with a rasping volley that flew into the top corner.
The visitors offered little in attack on an easy afternoon for Ben Foster as they slipped to a 15th league defeat of the campaign, David Moyes' side now three points from safety.
For Albion it was a welcome three points after being outclassed at Tottenham last time out and they remain in eighth position.
There was little in the way of quality in the final third in the opening 20 minutes as the ball got stuck in midfield far too much but West Brom gradually found their feet.
Nacer Chadli was given plenty of room 20 yards from goal but his well-struck effort was straight at Vito Mannone, and soon after Salomon Rondon's header looked set to drop in only for Matt Phillips to deflect it wide.
Sunderland's fortune did not last long, though, as the Baggies’ pressure finally paid off with Fletcher controlling a cushioned header from Gareth McAuley before volleying past Mannone on the half hour.
And Moyes' misery was doubled six minutes later as Brunt rifled a volley into the top corner after Chadli had hit the bar from six yards, Sunderland withering under Albion pressure
With the words of their manager no doubt ringing in their ears Sunderland made a positive start to the second half, however they failed to convert what little pressure they could muster into a clear chance.
Even when West Brom gifted an opportunity following a foul by Claudio Yacob, Patrick van Aanholt's effort smashed into the wall and the full-back then blazed the rebound well over.
Foster was finally called into action with 71 minutes played as Billy Jones met a right-wing cross from Sebastian Larsson but his header lacked power and the Albion keeper saved with ease.
The introduction of Victor Anichebe failed to spark the visitors into life, while Albion's new signing Jake Livermore was handed a late cameo.
He nearly added a third with eight minutes to play but skewed his volley wide.
It mattered little to the hosts, though, as they eased to a sixth game unbeaten against the Black Cats.