Peterborough 2 Albion 3 - Verdict
Albion survived a fine Peterborough fightback to claim another away win in the Championship.
The Baggies, who had Graham Dorrans sent off in the final seconds, led 3-0 but Posh struck back twice before the visitors held firm in a tense finale.
Roberto Di Matteo's side were cruising, as two goals from Luke Moore and one from Chris Brunt gave them a commanding lead.
But they allowed their hosts back into the game, with Craig Mackail-Smith striking in first-half stoppage time and Aaron McLean making it 3-2 early in the second half.
Albion began the night without captain Jonathan Greening, who was missing from the team following weeks of speculation over a move to Fulham.
The 30-year-old was omitted by head coach Di Matteo, who will now be expected to explain his decision.
And the Baggies were gifted the lead in the third minute, when Gabriel Zakuani's error let in Moore and his low shot crept past goalkeeper Joe Lewis.
Moore added the second on 34 minutes, when he finished a crisp move involving Marek Cech and Chris Wood with a powerful shot.
Then new signing Shaun Cummings galloped forwards on the overlap to cross for Chris Brunt to make it three.
But Posh gained fresh hope on the stroke of half-time, when Shaun Batt crossed from the left and Craig Mackail-Smith nipped in to head home.
Things got even more nervous for the visitors when George Boyd's low cross was turned in by the sliding McLean eight minutes into the second half.
Posh even had a third 'goal' from Mackail-Smith, ruled out for a push by McLean on skipper-for-the-night goalkeeper Scott Carson.
Dorrans then received his marching orders in stoppage time for a second bookable offence - a reckless late tackle on Charlie Lee.