ALL the action from the capital as Albion suffered last-gasp heartache in the opening game of 2018.
An Andy Carroll double saw West Ham run out 2-1 winners at the London Stadium.
James McClean's deflected strike from distance, his first goal of the season, handed the Baggies the lead at the break.
Yet Carroll's header on the hour mark levelled matters, before the West Ham striker struck deep into added time to give the Hammers all three points.
McClean, Claudio Yacob, Grzegorz Krychowiak and Salomon Rondon were all recalled as Head Coach Alan Pardew rotated his ranks with just 48 hours' rest from the New Year's Eve draw against Arsenal.
Yet Albion suffered a blow pre-match as Matt Phillips, due to start, was withdrawn due to precautionary measures having reported a tight hamstring in the warm-up, to be replaced by Jake Livermore.
It was fit-again Rondon who lofted Albion's first opening on to the roof of the net after 13 minutes with Adrian caught off his line.
Manuel Lanzini drew a strong save from Ben Foster before McClean and Jay Rodriguez both tried their chances from distance at the other end.
It was second time lucky for McClean on the half hour as he drove forward to the edge of the penalty area, cut inside on to his left foot and saw his strike flick off Angelo Ogbonna before looping over Adrian and into the top corner.
Foster pulled off an even better save to deny Lanzini again before blocking at close range from Cheikhou Kouyate, while Jonny Evans almost poked home a second for the Baggies just before half-time.
Carroll fired off target from six yards at the start of the second half but he made no mistake on the hour, rising high to head home from Aaron Cresswell's ball into the box.
Foster produced another fine save to deny Marko Arnautovic, with Pardew turning to Hal Robson-Kanu and Oliver Burke off the bench.
Burke's pace saw him race clear only to be denied by Ogbonna's block while Adrian tipped over from Craig Dawson's cross late on.
Burke then saw a volley fizz over the bar as both sides pressed for a winner.
But with the match heading for a stalemate, Carroll popped up at the back post to drill home Arnautovic's over-hit delivery.
ALBION: Foster, Dawson, Hegazi, Evans (c), Gibbs, Krychowiak, Yacob (Barry 83), Rodriguez (Burke 71), Livermore (Robson-Kanu 64), McClean, Rondon.
Subs: Myhill, McAuley, Brunt, Field.