Danny Dichio maintained West Brom's push foran automatic promotion place with the winner at Wimbledon.
Dichio carries a heavy weight on his shoulders, replacing top scorer Jason Roberts who is out for the rest of the season with a broken foot.
The former Sunderland striker responded wih the only goal of the game as the Baggies grabbed a vital win, despite being outplayed for long periods.
Wimbledon started quickly, and visiting goalkeeper Russell Hoult went full-length to turn Neil Shipperley's 20 yarder round the post.
The Dons looked determined to continue their five-match unbeaten run and Hoult again had to be on his toes when Peter Hawkins tried his luck from distance.
Third-placed West Brom's play looked disjointed as they tried to come to terms with life without Roberts.
Damien Francis and Agyemang both went close from distance but Wimbledon could not make the breakthrough their first-half play deserved.
Shipperley tested Hoult with a header at the start of the second-half.
With Wimbledon looking likely to break the deadlock, West Brom took the lead.
Igor Balis chipped a delightful ball in and Dichio made no mistake, guiding his 52nd minute header into the top corner from six yards.
Albion began to take control, with Andy Johnson going close from distance a couple of times as the visitors looked to safeguard the three points.
Wimbledon, though, regained their composure and set about getting back on terms.
Andersen tested Hoult with a header from Ardley's corner but West Brom still looked dangerous in the break.
In a frantic finale, Jordao and substitute Bob Taylor both almost doubled the visitors' lead before Lionel Morgan's header went close for the Dons.
Ardley examined the West Brom defence with a succession of late corners but Hoult dominated in the Baggies goal to help his team secure a vital victory.