A one-sided first half saw the Baggies take control of the clash and forced Wednesday to settle for a storm-weathering session with only Djeidi Gassama offering a great deal in terms of an outlet. The second half turned along with a system switch-up and Owls substitutes made a difference - with chances falling to the away side as the game went on.
A classy Adam Armstrong finish seemed to set up a home win before subs Svante Ingelsson and Callum Paterson combined to grab what could have been a dramatic equaliser - before Jason Molumby diverted a last-gasp corner home to take the three points.
Here are our ratings from another topsy-turvy afternoon with Sheffield Wednesday.
1. James Beadle - 8
Good save from a corner and out smartly to punch a few minutes later. Made an excellent sprawling stop not long after that, to boot. Weathered a storm in the first half particularly. | UGC
2. Yan Valery - 6
A strong effort in both directions. Got his foot in, played different roles and put in a dangerous cross. | UGC
3. Michael Ihiekwe - 7
Is he suddenly Wednesday's most important footballer? Made some important interventions and seemed to enjoy playing colonel in the trenches for periods. Headed over late on. | UGC
4. Di'Shon Bernard - 5
Took one off the foot of Armstrong early doors. Looked late to a few bits and not quite himself. Tried to run off an injury but had to come off before the break. Bizarrely booed off. | UGC