A CONTROVERSIAL 69th-minute penalty cost Albion dear in the battle at the bottom as they suffered defeat at Selhurst Park.
The Baggies gave themselves a mountain to climb by gifting Eagles debutants Thomas Ince and Joe Ledley goals - and the hosts a 2-0 lead after just 27 minutes.
But Albion’s own new boy and half-time substitute Thievy gave the visitors a lifeline within 40 seconds of the restart with his first goal on his Barclays Premier League bow.
Pepe Mel’s men appeared to be in the ascendancy as they probed for an equaliser but referee Chris Foy harshly adjudged Ben Foster to have felled Marouane Chamakh in the box on 68.
TV replays clearly showed the England goalkeeper took the ball – but the Morocco international picked himself up to kill the game off from the resultant spot-kick.
Mel made two changes to his side – one enforced – as James Morrison and Craig Dawson came in for the benched Saido Berahino and injured Jonas Olsson (hamstring).
Tony Pulis freshened his team up with three new faces as January signings Thomas Ince, Scott Dann and Joe Ledley were all handed debuts.
Chris Brunt’s incisive 40-yard pass put Victor Anichebe in the clear in the sixth minute – but he failed to generate any power in his shot as Scott Dann challenged him 15 yards out and Julian Speroni saved comfortably.
Three minutes later an Eagles corner bounced off Brunt – as he was pressured by Kagisho Dikgacoi – towards his own goal.
Fortunately, Mulumbu was on the goalline to block and saw the rebound cannon off Dann and over the bar.
Five minutes later Yannick Bolasie was allowed to get on the end of Jason Puncheon’s diagonal cross to the back post and Ben Foster grabbed the DR Congo international’s header on the line.
But the hosts did break the deadlock just moments later as Marouane Chamakh challenged Gareth McAuley from Joel Ward’s aerial ball and the Baggies defender’s header dropped into the path of Bolasie.
He lost his footing as he knocked it forward and Thomas Ince was first to react to the loose ball in the penalty area as he nipped in between McAuley and Billy Jones to dink home over Foster.
McAuley nodded Brunt’s back-post corner back across goal on 25 and it fell invitingly for Dawson, who volleyed well over from six yards, when he should at least have hit the target.
Things went from bad to worse in the 27th minute as Joe Ledley wriggled free of Jones and ran onto fellow Palace debutant Ince’s in-swinging corner from the right to power home a header and double the lead.
Two minutes later Chamakh looked to have slotted Ince through on goal – but Foster raced to the edge of the box to kick clear.
Palace struggled to clear a Brunt free-kick on 40 and it eventually fell to Youssouf Mulumbu 20 yards out.
He let fly with a goalbound shot that Ledley managed to deflect wide with his head.
Mel made an adventurous double change at the break as he handed a debut to Thievy and brought on former Palace loan winger Scott Sinclair.
The men to make way were Zoltan Gera and Liam Ridgewell, with Brunt dropping to left-back.
Sinclair started on the left-wing and Thievy joined Anichebe in attack.
Within 40 seconds that combination paid dividends as Thievy raced in off the left touchline and exchanged passes with Anichebe before firing a crisp ten-yard finish past Speroni at his near post.
Ince broke dangerously past Dawson into the penalty area on 58 – but McAuley was on hand to clear with a well-timed sliding challenge.
Four minutes later Ince’s low in-swinging flag-kick from the right crept through to the goalline, where Jones was able to clear before Chamakh could bundle the ball home.
Thievy ran onto Anichebe’s flick in the 65th minute and as he was challenged by Damien Delaney the ball fell nicely for Morrison, whose fierce 25-yard drive was beaten out by Speroni.
Seconds later Mulumbu’s shot was deflected into the path of Sinclair, who saw Speroni pull off a point-blank save from his volley.
It was Albion doing all the pressing – but on 68 Chamakh chased clear and, although TV replays showed Foster took the ball, referee Chris Foy pointed the penalty spot.
The Eagles striker picked himself up to slot home the spot-kick as he sent Foster the other way.
On 71 both sides made a change as Berahino came on for Yacob for the visitors and Glenn Murray replaced Puncheon for the hosts.
With around ten minutes remaining Morrison tested Speroni with a near-post drive and Anichebe then spun on a Morrison pass – but got his angles all wrong with his 15-yard effort.
At the death Palace were struggling to clear their lines and the ball rebounded off Berahino and just the wrong side of the right-hand post.
PALACE (4-2-3-1): Speroni; Ward, Dann, Delaney, Ledley; Dikgacoi, Jedinak; Puncheon (Murray 71), Ince, Bolasie (Parr 75); Chamakh (Thomas 83). Subs not used: Hennessey, Parr, Gabbidon, Bannan, Gayle.
ALBION (4-2-3-1): Foster; Jones, McAuley, Dawson, Ridgewell (Sinclair HT); Yacob (Berahino 71), Mulumbu; Gera (Thievy HT), Morrison, Brunt; Anichebe. Subs not used: Myhill (gk), Lugano, Vydra, Dorrans.
GOALS: PALACE – Ince (15), Ledley (27), Chamakh (pen 69); ALBION – Thievy (46).
BOOKINGS: ALBION – Yacob (foul 64), Brunt (foul 79).
REFEREE: C Foy (Merseyside).
ALBION STARMAN: Thievy.