West Brom skipper Sean Gregan scored his first goal for the club to earn them their third successive victory against 10-man Southampton at The Hawthorns.
The defeat was a nightmare for the Southampton goalkeeper Paul Jones who fumbled Gregan's hopeful 35-yard drive into his own net 21 minutes from time.
Southampton, who also had central defender Paul Williams sent off in the 85th minute after he collected his second booking, should really have wrapped up back to back wins before Jones' fumble.
Strikers James Beattie and Marian Pahars both wasted golden chances and the misses came back to haunt Southampton when Gregan struck.
Pahars should really have put them in front after 18 minutes, but he fired wide when faced with only Albion goalkeeper Russell Hoult to beat.
Gregan and Hoult then failed to deal with a bouncing ball on the stroke of half-time, allowing Beattie to head the ball towards an empty net.
Fortunately for Albion, back-pedalling central defender Phil Gilchrist was on hand to hack the ball off the line.
Albion were then indebted to Hoult 14 minutes into the second-half for a stunning save to deny Pahars.
Pahars created the chance himself, taking the ball off Albion substitute Larus Sigurdsson before seeing his shot saved at full stretch by Hoult.
It proved to be a vital intervention by Hoult as Albion took full advantage of the let-off when Gregan grabbed his first goal for the club since his £2million summer move from Preston and secured Albion's third successive 1-0 win