ROBERTO Di Matteo's side made history as they battled back to earn the draw they needed to hit the 90-point mark - the best-ever haul by a Baggies side in a league season.
The tally surpasses the 89 Gary Megson's 2002 promotion-winners amassed - which was also reached against Palace - as Albion extended their unbeaten run to 11 games.
In one of the Coca-Cola Championship's games of the season, Steven Reid's 17th-minute own goal gave the relegation-threatened Eagles the ideal platform to secure the win they needed to guarantee safety.
But their lead lasted less than four minutes as Gabriel Tamas equalised with his second goal of the season in the 21st minute.
And the Baggies would have gone on to clinch all three points had it not been for the woodwork and a series of saves from the outstanding Julian Speroni in the Palace goal.
The dismissal of former Blues midfielder Neil Danns for a head-butt on Graham Dorrans seven minutes from time did not help the Eagles' cause.
And they must now avoid defeat in a relegation showdown at Sheffield Wednesday on the final day of the season to avoid the drop to League One.
Di Matteo named an unchanged team for the third successive game.
Paul Hart made two changes to his Eagles team, with Matt Lawrence and Calvin Andrew replacing the benched Nick Carle and absent Lee Hills.
Palace threatened first in the fourth minute but Sean Scannell could not stretch far enough at the back post to make contact with Darren Ambrose's left-wing cross.
Nine minutes later, workaholic Simon Cox out-muscled Clint Hill to bundle Chris Brunt's left-wing centre into the goal.
But referee Dean Whitestone ruled it out for handball by the Baggies hitman - and booked him.
Albion had yet to find any real rhythm when they fell behind on 17.
Reid found himself in an awkward position in the six-yard box as Ambrose swung in a terrific right-wing free-kick and he ended up putting through his own net.
But the hosts' lead lasted less than four minutes as Albion responded in some style.
On-loan Auxerre centre-half Tamas beat Hill to Brunt's right-wing free-kick at the near post and headed into the top right-hand corner of the net to equalise.
Brunt tried his luck from 30 yards on the half-hour mark but his skidding shot was comfortably dealt with by Speroni.
Ambrose managed to find Danns in the penalty area two minutes later and he forced Scott Carson into a superb save with a 12-yard drive.
Jonas Olsson could only scoop the rebound back towards his own goal and the off-balance Andrew headed wide of the empty net.
But Albion took complete control for the rest of the half and only they will know how they failed to go into the break in front.
Bednar played a first-time pass to Cox in the 35th minute and he burst past Patrick McCarthy before seeing Speroni beat out his fierce effort from just inside the box.
A minute later, superb skill by Dorrans saw him coast past two Palace defenders before standing up a near-post cross that Bednar headed against the crossbar.
Both Robert Koren and Olsson looked certain to score as they challenged for the rebound in front of the empty net but they ended up getting in each others' way and the ball somehow ballooned over the empty net.
Six minutes before the break, Bednar's reverse pass put Brunt clean through on goal.
The Northern Ireland international saw Speroni save his strike and Koren picked up the loose ball on the edge of the area, but was dispossessed.
Brunt then teed up Dorrans in the 43rd minute and the Scotland international wasted little time in letting fly with a dipping volley that forced Speroni into a fine one-handed save just under his bar.
Two minutes later, Speroni hesitated as Dorrans played the ball through and Bednar stole in to clip a left-foot shot past the Argentine keeper - and the right-hand post.
Dorrans and Cox then both had shots blocked in the penalty area as the Eagles somehow held out to keep the scores level at the break.
Albion were back on the front foot after the restart, with Cox volleying Olsson's long ball over the bar within a minute.
The flag went up for offside - but TV replays showed he wasn't.
Brunt played a quick one-two with Cox from a corner in the 49th minute and swung in a cross that fell for Koren.
The Slovenia skipper's ten-yard volley lacked the pace and direction to beat Speroni, who gathered the ball at the second attempt before Olsson could get a touch.
Palace finally threatened again on 57 when Scannell cut inside from the right and found Ambrose, who forced Carson into a low save to his left with an 18-yard strike.
Bednar had a glorious chance to give the visitors the lead on the hour mark as he raced clear from Tamas' throughball.
But the Czech hitman was thwarted by Speroni, who forced him wide.
McCarthy had a golden opportunity for the hosts six minutes later, only to head Ambrose's free-kick wide at the back post.
Moments later at the other end, Tamas out-jumped everyone from Brunt's right-wing corner to head over.
And Cox then had McCarthy twisting and turning before seeing Speroni save his low 25-yard shot.
Hart made a change in the 68th minute as Alan Lee came on for Scannell.
That was quickly followed by a Baggies switch, with Giles Barnes replacing Koren.
Lee latched onto Danny Butterfield's pass in the 75th minute and beat Olsson before seeing Carson pull off a good save to deny his shot.
From the resultant Ambrose corner, Matt Lawrence headed over when he should at least have hit the target.
Eight minutes from time, Dorrans teed up Marek Cech who saw Speroni save his effort before Dorrans poked the rebound just wide of the right-hand post.
The hosts were reduced to ten men in the 83rd minute when Danns was sent-off for head-butting Dorrans, who was also booked, following a tussle between the two players.
Two minutes later, James Morrison came on for Dorrans.
Albion had already created countless chances and they went agonisingly close again on 86 when Butterfield just managed to scoop the ball over his own bar from Brunt's cross.
Three minutes later, Speroni did well to hold Bednar's header from Brunt's corner.
Youssouf Mulumbu wondered through the Palace defence in the 90th minute before forcing Speroni into another save with a powerful 15-yard drive.
But the hosts came close to nicking it in the third minute of stoppage time when substitute Stern John headed inches wide from Ambrose's back-post cross.
And, with virtually the last kick of the game, Cech cleared Ambrose's shot off the goalline.
PALACE (4-5-1): Speroni; Butterfield, McCarthy, Lawrence (N'Diaye 90), Hill; Ambrose, Danns, Derry, Ertl (John 77), Scannell (Lee 68); Andrew. Subs not used: Mann (gk), Clyne, Carle, Davis.
ALBION (4-5-1): Carson; S Reid, Tamas, Olsson (Meite 78), Cech; Koren (Barnes 71), Cox, Mulumbu, Dorrans (Morrison 85), Brunt; Bednar. Subs not used: Kiely (gk), Mattock, Wood, Mantom.
GOALS: PALACE - Reid (og 17). ALBION - Tamas (21).
BOOKINGS: ALBION - Cox (deliberate handball 13), Reid (foul 18), Bednar (foul 73), Olsson (foul 74), Dorrans (unsporting behaviour 85).
SENDING-OFF: PALACE - Danns (violent conduct 83).
REFEREE: D Whitestone (Northamptonshire).
ATTENDANCE: 17,798 (Albion fans 1,227).
ALBION STARMAN: Graham Dorrans.