Albion's dismal start to the new year continued with a 2-1 defeat at Cardiff City.
The Baggies were bullied throughout by the Cardiff's physical approach and twice saw defensive frailities punished by the hosts.
In arguably Albion's poorest performance of the season, Callum Paterson poked home the first seconds into the second half after a comedy of errors from the Baggies' backline.
Substitue Charlie Austin levelled the scores with his first touch from the penalty spot after brilliant work from Filip Krovinovic saw the Croation felled in the area.
But Albion wilted again with 15 minutes remaining when Kyle Bartley's weak pass was intercepted and Lee Tomlin was brought down on the edge of the area. The striker picked himself up curled in a brilliant free kick to give the Bluebirds a deserved victory.
"We knew it wasn't going to be a pretty game, they are very direct and very aggressive team. We wanted to stop them creating anything, even from throw-ins. We were pretty solid on paper at least," a down-beat Slaven Bilic said after the final whistle.
"We expected a game of very few chances and knew it wasn't going to be easy to score against them. You can't concede goals like that.
"It's simply not good enough at the moment. Told the guys we need to look at each other, not as soon as possible - but now, to what get back what we had. We don't have it in the moment. We can't say we were unlucky for seven games, can't blame anybody but us. We have to get it back. Simple as that. We weren't good enough.
"I can't be any harder, I spoke quite long in the dressing room. We need it back, we need the team back. We have to get back on winning track, first of all stop conceding goals."