The Czech Republic striker slotted in four minutes from time to earn the Baggies a valuable point against Steve Bruce's men, who had taken the lead through Jake Livermore.
Matej Vydra's first West Brom goal rescued a 1-1 draw against Hull City on Saturday in caretaker boss Keith Downing's first game in charge.
Downing took over as caretaker boss at West Brom following Steve Clarke's dismissal a week ago, and was able to prevent a fifth straight defeat thanks to a late goal from substitute Vydra at the Hawthorns.
Jake Livermore's strike was the only talking point of a relatively dour first half, with the lively midfielder calmly finishing a one-on-one after 28 minutes.
|VIEW FROM THE HAWTHORNS
|By Tom Davis
It’s been a particularly busy period for the Baggies given the sacking of their manager this time last week, so a point today is welcome.
Keith Downing started his reign as caretaker with little goalmouth action, succumbing to a Jake Livermore goal from the visitors who, up to the interval, were looking comfortable.
But Saido Berahino's introduction at the break injected his side with plenty of drive and vigor going forward, and they duly equalized through Matej Vydra.
On their Christmas list is a new manager but a point is a fine stocking filler and a just result for both sides.
Livermore looked to have registered the only goal of the game but Vydra rolled home an effort from inside the area to salvage a point for the hosts and deny Steve Bruce's men their second away league win of the season.
Downing recalled Ben Foster and Scott Sinclair from foot and hamstring injuries respectively while James Morrison earned a recall to the starting XI.
Bruce's Hull side was unchanged from the 0-0 draw with Stoke City last time out as defender Alex Bruce shook off a groin problem to retain his place.
Following a quiet opening spell, which saw both sides cancel one another out in midfield, the visitors hit West Brom on the counter to take the lead.
Danny Graham retained possession well after breaking away and, when support arrived in the form of Livermore, he played in the Tottenham loanee, who slid the ball under the onrushing Foster.
David Meyler's deflected effort almost looped in to double the visitors' advantage six minutes later, while Sinclair came close to fashioning a clear chance, only to be denied by a last-ditch James Chester tackle.
After Saido Berahino had replaced Sinclair at halftime, the home side started the second period brightly and Stephane Sessegnon stung the palms of Allan McGregor with a fierce effort.
McGregor was also equal to Gareth McAuley's header before Foster pulled off a double save to deny Tom Huddlestone and Ahmed Elmohamady.
Morrison fired a long-range effort over the bar after 72 minutes but, just when it appeared that West Brom was set for defeat, Vydra applied the finishing touch to a fine move, slotting home Zoltan Gera's through ball four minutes from time.
Despite seeing victory snatched away late on, Hull was able to extend its unbeaten run to three matches thanks to a third consecutive draw.