West Brom's automatic promotion hopes were hit at The Hawthorns by Victor Moses' equaliser for Crystal Palace.
The Baggies went ahead on the half-hour mark when Kevin Phillips struck his 200th career goal, superbly controlling a pass and lifting the ball home.
James Morrison fizzed a shot wide before Palace levelled, Jamie Scowcroft heading into Moses' path, the teenager taking a touch and side-footing in.
Julian Speroni saved brilliantly from Phillips as Palace held on for a point.
West Brom boss Tony Mowbray:
"They had a game plan which smothered the midfield and denied us any fluency. The opening 20 minutes of the second half was disappointing.
"It looked like we took a step back and allowed them to build up a bit of momentum which culminated in the goal.
"But looking at the results on Tuesday everyone is finding it hard to win."
Crystal Palace boss Neil Warnock:
"It's a super point. There's not many easy places to go as it seems that everyone is fighting at one end of the table or another.
"We knew what kind of team they have got and they could have put an equally good team out with who they left out.
"One lapse of concentration and we got punished. That's where your real top players come into it."
West Brom: Kiely, Hodgkiss, Albrechtsen, Barnett, Robinson, Gera (Moore 67), Greening, Koren, Brunt (Morrison 40), Phillips, Miller, Morrison (Kim 46).
Subs Not Used: Bednar, Martis.
Goals: Phillips 30.
Crystal Palace: Speroni, Lawrence, Hudson, Fonte, Hill, Soares (Morrison 45), Watson (Hughes 88), Fletcher, Derry, Moses (Scannell 61), Scowcroft.
Subs Not Used: Hills, Robinson.
Goals: Moses 55.
Ref: Peter Walton (Northamptonshire).