GIANNI Zuiverloon's second goal in three games fired depleted Albion back to the top of the table on goal difference.
The Baggies had to contend with a manpower crisis on their first-ever trip to the Cardiff City Stadium and fell behind to an eighth-minute Peter Whittingham penalty.
But Roberto Di Matteo's men regrouped admirably and deservedly levelled on the stroke of half-time when Zuiverloon bundled home his fourth of the season.
The visitors will feel somewhat aggrieved they did not seal a fifth successive league win in South Wales, with Andy Slory hitting the post in the first half and sub Chris Wood spurning a gilt-edged chance with 20 minutes to go.
But a ninth successive game without defeat - making it 13 unbeaten on the road - in such testing circumstances underlined the never-say-die character of this Baggies side.
Albion started the day three positions and 11 points better off than fifth-placed Cardiff, who have a game in hand on the Baggies.
Di Matteo made four changes as he attempted to cope with the loss of NINE players through injury and suspension.
Roman Bednar became the latest casualty, being relegated to the bench with a back injury. Slory (Achilles), Gabriel Tamas, Frank Nouble and Luke Moore came in, with the benched Simon Cox, Gonzalo Jara (foot) and Abdoulaye Meite (ankle) also making way.
Academy players Sam Mantom and Kayleden Brown, plus 19-year-old rookie midfielder Joss Labadie, were among the subs.
Cardiff were unchanged from their FA Cup exit at Chelsea.
The hosts were the first to threaten but Gavin Rae failed to trouble Scott Carson with a scuffed 20-yard effort from Chris Burke's square ball.
But Moore went much closer in the fourth minute, flashing a 15-yard shot on the turn inches wide of the beaten David Marshall's far post from Graham Dorrans' pinpoint ball over the top.
However, after a lull in proceedings, Cardiff snatched an eighth-minute lead after Jonas Olsson got caught the wrong side of Jay Bothroyd, who advanced into the box before being pulled down by the Swede.
Whittingham made no mistake from the spot, powerfully driving his 19th goal of the season past the helpless Carson.
Albion responded immediately and after a surging run by Dorrans, only Anthony Gerrard's interception denied Moore a tap-in from Nouble's left-wing centre.
Brunt then saw a tame 25-yard drive easily gathered by Marshall.
Cardiff were happy to sit back on their lead - which invited Albion forward.
And Marshall was relieved to see Dorrans' 25-yard exocet from Joe Mattock's miscued centre screw wide of his left-hand post.
Albion kept pressing and were mightily unlucky not to level on 24.
A great move involving Dorrans and Moore set up Slory, who saw his 12-yard drive bounce off the inside of the far post and straight to Kevin McNaughton.
Whittingham's evening went downhill after his breakthrough from the spot and the former Villa midfielder limped off in the 27th minute, being replaced by Ross McCormack.
Cardiff finally made a foray into the Baggies half a minute later and, from Bothroyd's lay-off, Burke well and truly stung Carson's hands with a 20-yard piledriver which the England international pushed away.
There was more Albion agony on 38 when Zuiverloon's long throw-in wreaked havoc in the Bluebirds' box.
Robert Koren reacted brilliantly to the bouncing ball, only to see his acrobatic volley fly straight at Marshall.
The Cardiff keeper fumbled the shot but the ball again flew to a blue shirt.
But Albion kept plugging away and deservedly levelled four minutes into first-half stoppage time.
Dorrans picked out Zuiverloon's foraging run with a sublime diagonal ball into the box and the right-back saw his goalwards stab deflect off Marshall and loop onto the far post before dropping over the line.
Albion picked up from where they left off after the interval and Brunt saw a 15-yard snapshot fly into the side-netting after terrific hold-up play by Nouble in the 49th minute.
Cardiff did not threaten again until the 56th minute when Gabor Gyepes wastefully planted a free header from McCormack's free-kick straight at Carson.
City were much-improved after the break and, moments later, Rae blasted an ambitious 25-yard drive well wide.
Back came Albion and Gerrard had to produce a timely near-post clearance from Nouble's low centre to deny the lurking Koren and Moore a certain goal after a terrific Baggies counter-attack.
Di Matteo made his first change on 64, replacing the tiring Slory with Wood.
And the New Zealand international should have put Albion ahead six minutes later.
The 18-year-old used all of his brute strength to get on the end of Zuiverloon's pinpoint centre, only to direct a free header wide from six yards.
But Albion had a huge let off five minutes from time when Olsson played Michael Chopra's harmless pull-back straight to Burke inside the box.
The former Rangers winger beat Carson all ends up with a first-time shot from 15 yards - but the ball flew wide of the far post.
Incredibly, Albion went agonsingly close to winning it in stoppage time when sub Cox almost forced Dorrans' terrific corner over the line in a goalmouth melee.
CARDIFF(4-4-2): Marshall; McNaughton, Gyepes, Gerrard, Kennedy; Burke, Rae, Wildig (Blake 70), Whittingham (McCormack 27); Chopra, Bothroyd. Subs not used: Enckelman (gk), Quinn, Taiwo, Feeney, Matthews.
ALBION (4-5-1): Carson; Zuiverloon, Tamas, Olsson, Mattock; Slory (Wood 64), Koren (Cox 83), Dorrans, Brunt, Nouble; Moore. Subs not used: Kiely (gk), Bednar, Brown, Mantom, Labadie.
GOALS: CARDIFF - Whittingham (8 pen). ALBION - Zuiverloon (45+4).
BOOKINGS: ALBION - Tamas (foul 33), Dorrans (unsporting behaviour 53), Koren (handball 55), Mattock (foul 78).
REFEREE: A Woolmer (Northamptonshire).
ALBION STARMAN: Graham Dorrans.