ALBION started their 2018/19 Sky Bet Championship campaign with an opening-day defeat to Bolton Wanderers.
Debutant Harvey Barnes levelled with an exceptional 30-yard strike into the top corner on the stroke of half-time after Josh Magennis had headed Wanderers into the lead.
But Yanic Wildschurt somehow squeezed the ball home from an 89th-minute corner to give the travelling Trotters all three points.
Darren Moore's side largely dominated the encounter but despite going close, Ahmed Hegazi seeing his header hit the bar, could not find a reply to send home a sold-out, sun-bathed Hawthorns crowd celebrating a share of the spoils.
The Baggies now travel to the City Ground to face Nottingham Forest in their next league encounter on Tuesday.
Albion, backed by a racous home support, made a positive start to proceedings in the opening stages.
However, it was Wanderers who broke the deadlock in the 18th minute when Sammy Ameobi crossed for Magennis to head home from inside the six-yard area.
Mark Beevers almost headed a quickfire second for the Trotters while Allan Nyom and Matt Phillips both went close from distance at the other end.
Hegazi headed a good chance off target from Barnes' cross and, with half-time approaching, it was the on-loan Leicester winger who delivered a goal of superb quality to level matters.
Picking up the ball on his more unnatural right side, Barnes cut in on to his left foot and curled a stunning 30-yard strike into the far top corner.
Livewire Barnes saw an attempt blocked at the start of the second half as the Baggies contined to assert themselves.
Hegazi's close-range header was well tipped over by visiting keeper Ben Alnwick just after the hour mark, before Magennis' header was kept out by Johnstone.
Matt Phillips flashed a strike across the face of goal but it was not to be as the Baggies suffered a late blow.
Wildschurt reacted quickest to David Wheater's knockdown, steering the ball beyond Johnstone and into the far corner with just two minutes of normal time remaining.
Egypt international Hegazi again made a nuisance of himself from a corner in a quest to save a point. But his effort cannoned off the bar and away to safety.
ALBION: Johnstone, Nyom, Bartley, Hegazi, Gibbs, Phillips, Livermore, Brunt, Barnes (Burke 76), Rodriguez, Robson-Kanu.
Subs: Myhill, Townsend, Adarabioyo, Harper, Barry, Morrison.