LATICS failed to make it three Premier League wins on the spin as they crashed 2-1 at home to West Brom.
The home side enjoyed the lion’s share of possession and territory, but lacked a cutting edge to really trouble the in-form Baggies.
James Morrison scored the first goal with a bullet header from Chris Brunt’s inviting delivery.
And Latics gave themselves a mountain to climb when Billy Jones’ shot was deflected past Ali Al Habsi by an unfortunate Gary Caldwell.
Arouna Kone pulled one back within a minute - a close-range finish - to give Latics hope at half-time.
But try as they might, they were unable to restore parity in the second period.
Perhaps the best chance fell to Shaun Maloney, but the Scotland star couldn’t keep his effort down from just inside the box.
And Latics knew it wasn’t going to be their day when Jean Beausejour’s cross found Franco di Santo unmarked on the far post, only for the Argentine to head the ball into team-mate Kone and over the bar.