West Brom fell into the bottom half of the EFL Championship on Monday night as Steve Bruce's hunt for a first win in charge of the club continued.
After a game where chances were few and far between, a quick-fire double from Swansea City,, courtesy of Joel Piroe and Cyrus Christie secured all three points in a fine showing for the visitors.
Pre-game
The hosts came into the game looking to break a six-game winless run, against visiting opposition who were seeking to bounce back from a 4-0 defeat at Sheffield United last time out.
West Brom made just one change to their team that lost 2-1 to Middlesbrough in their last game, with Callum Robinson returning to the side in place of leading scorer Karlan Grant.
A host of changes were made by Swansea, with Finley Burns, Olivier Ntcham and Joel Latibeaudiere being replaced with Kyle Naughton, Hannes Wolf and Michael Obafemi.
Story of the game
In an opening period where neither side could cut out a clear chance, it took until the 20th minute for someone to get a go as Robinson's fine header from Dara O'Shea's cross bounced off of the upright.
The Hawthorns crowd was made to wait another 20 for a second chance, as Andy Caroll nodded a free-kick over to Semi Ajayi, who subsequently headed over to Kyle Bartley whose effort was spiked into the ground.
West Brom's frustrations in the final third continued just a minute later, as Diangana prodded a Robinson cross wide under pressure.
Out of nowhere, Swansea responded in the 41st minute with their best chance of the half as Obafemi collected a Joel Piroe pass to lay off Swans captain Matt Grimes, who directed a ranged effort past the post.
Swansea came on strong in the back end of the half, as Cyrus Christie headed a fine Ryan Manning corner towards goal, only to be denied by Sam Johnstone as the teams went in at the interval goalless.
Chances were just as hard to come by in the second half, as Piroe was denied by the outside of the post after rampaging into the box just four minutes after the restart.
Robinson and Diangana again combined in the 66th minute, with the former finding the latter to force a fine stop from Johnstone before the flag went up.
Obafemi was the next man to find an opportunity in the box, misfiring a cut-back from Manning behind for a corner.
Moments later Obafemi fluffed his lines again, as Manning again picked the Ireland international out with a fantastic cross, but the on-loan Southampton striker headed over.
Robinson's heart-wrenching love affair with the right-hand post continued in the 76th minute, as his driving run from the halfway line resulted in a bending effort that bounced agonizingly off of the woodwork.
The deadlock was finally broken just three minutes later, as substiute Ntcham affected the game instantly with a lung-busting run down the left hand-side, before cutting the ball back for Piroe to slide home his 15th goal of the season through the legs of the Johnstone.
The lead was doubled in the 84th minute to a chorus of booing from the home crowd, as a swift counter-attack from the Swans saw Wolf free on the left to slide the ball across for Christie to smash past Johnstone, who could not get enough on the strike to keep it out.
West Brom didn't really come forward again from that point, as Swansea held firm to see out a well-won three points.
Man of the match - Joel Piroe
He nearly assisted a world-beater from Grimes and nearly had one of his own, but the Dutch striker eventually slotted home the deadlock breaker when his side needed it most.
His running and ability on the ball were constant threats for West Brom, and he thoroughly deserved to come away with a goal to his name.