QPR came back from two down to secure a potentially crucial point in the battle to stay up.
Having lost nine of their previous 10 matches and all but one of seven since Gareth Ainsworth took over as boss, Rangers looked to be heading for another defeat after early goals from Brandon Thomas-Asante and Semi Ajayi.
But they pulled off an unlikely fightback, with Lyndon Dykes halving the deficit and Chris Martin equalising.
It moved Rangers up to 20th, above Cardiff, who lost to Sunderland, and two points clear of third-from-bottom Reading, who conceded a late goal to lose 2-1 at Preston.
Ainsworth made changes for the game at The Hawthorns, switching to a 4-4-2 formation with Jimmy Dunne deployed as a right-back and Albert Adomah on the right wing, with Martin restored up front and Chris Willock dropped to the bench.
But Rangers’ all-too familiar habits of dismal defending and conceding early goals were on show once again.
They went behind after just 10 minutes. Rob Dickie gave away a free-kick on the left and John Swift’s delivery was missed by keeper Seny Dieng, with Thomas-Asante bundling home from a couple of yards out.
It was 2-0 less than four minutes later. Marc Albrighton sent in a low cross from the right and, after Swift’s shot was parried by Dieng, Semi Ajayi was able to nudge the loose ball over the line.
Another heavy QPR defeat looked a certainty at that stage, but they were galvanised by Dykes’ fine header from Ilias Chair’s right-wing cross on 22 minutes – Rangers’ first goal in four matches and Dykes’ first since November.
The visitors continued to look shaky at the back, but an Albion defensive howler enabled them to draw level four minutes into the second half.
Keeper Josh Griffiths struggled to control a back-pass and his attempted clearance was blocked by Martin, diverting the ball into the net.
Rangers almost went ahead when Taylor Richards headed wide from fellow substitute Jamal Lowe’s cross.
And another QPR substitute, Andre Dozzell, fired just wide of the target.
QPR: Dieng, Dunne, Dickie, Balogun, Paal, Adomah (Lowe 71), Amos (Dozzell 83), Field, Chair (Richards 83), Dykes, Martin.
Subs not used: Archer, Laird, Johansen, Willock.