Wigan missed a plethora of chances, showing a lack of confidence in front of goal in a game they should have won easily, and have now scored just 25 times in their 29 Premier League games this season, to leave themselves bottom of the table on goal difference.
James McArthur gave Wigan the lead shortly before the hour mark with only the club's ninth goal at home in the past 13 outings at the DW Stadium, but they were haunted by Paul Scharner, who was allowed to score against the club he left 19 months ago to earn Albion an unlikely draw in a game dominated by Wigan, despite their record of being winless at home since August.
"In many ways it's a really frustrating feeling, and I feel it's a football injustice, but I really enjoyed our performance and thought we controlled the game," said Roberto Martinez, the home side's manager,after the match. "The hardest thing in football is to create chances, and taking them sometimes comes from moments of form, or a bit of luck, or confidence. We haven't been able to create any momentum, and that's probably why we've lost so many points."
Four opportunities were wasted within the opening five minutes, the goal-shy Franco Di Santo guilty of three of them. The Argentinian striker, who hasn't scored since late November, forced Ben Foster to extend himself in the fifth minute as he tipped a shot from inside the area over the bar. From the resulting corner, an unmarked Gary Caldwell could only flick an effort wide from the edge of the six-yard box.
In recent weeks Wigan have lacked any threat in the box, but were trying to make amends by packing the area whenever their wide players had possession of the ball. This almost paid off on the quarter-hour as Maynor Figueroa crossed from the left and the bouncing ball was met by the impressive Emmerson Boyce, but his diving header ricocheted off the top of the bar and went over.
A Shaun Maloney corner in the 28th minute caused havoc within the Albion penalty area, as the defence could only clear the cross into the path of James McCarthy on the edge of the area, but his looping volley hit the crossbar. The rebound fell to Victor Moses one yard out, but the Nigerian failed to control the ball properly, allowing Foster to scramble it off the line and wide.
McArthur became only the second Wigan player to score a goal at the DW Stadium this year when he found the back of the net in the 54th minute. Moses bustled his way around two Albion players on the right-hand side before drilling a cross along the six-yard box which struck Maloney but landed straight at the feet of McArthur, who managed to toe-poke the ball beyond Foster and a covering defender on the line for his third goal of the season.
But going behind only served to rejuvenate the visitors, as Scharner headed home unmarked from a Chris Brunt corner 10 minutes later. The Austrian was restrained in his celebration, having made over 150 appearances for Wigan, but it showed the fragility of his former club's defensive unit at set-pieces, especially as Di Santo had headed the ball just over his own bar from another corner moments earlier.
West Bromwich's manager, Roy Hodgson, was relieved to leave Lancashire with a point. He said: "I was worried by the amount of crosses they were getting in, I thought they would score every time they got it into the box.
"I left a few players out of the team to give other players a go, so I've got to be very satisfied with a point, and sympathise with Wigan."
Wigan (3-4-3): Al Habsi; Alcaraz, Caldwell, Figueroa (Crusat, 90); Boyce, McArthur, McCarthy (McManaman, 80), Beausejour; Moses, Di Santo, Maloney (Diamé, 80).
West Bromwich Albion (4-3-3): Foster, Jones, McAuley, Ridgewell, Shorey, Scharner, Mulumbu (Andrews, 80), Morrison, Brunt, Long, Thomas (Dorrans, 86).
Referee: Michael Oliver
Man of the match: Boyce (Wigan)