Slaven Bilic had no complaints after Wigan's well deserved victory over the Baggies.
Sam Morsey fired in from close range after Albion had failed to clear a corner in the 73rd minute.
The defeat ended Albion's six game unbeaten run but Bilic admitted his side were well below the standards they have set so far this season.
“We were flat and didn’t have that energy, spark or the determination to take control of the game,” he told the club's official website.
“It’s very disappointing but we have to say a draw would’ve been fair but no more than that.
“We didn’t manage the ball well, we weren’t direct and failed to keep the ball. Yes they are a good team that is in form, but so are we.
“We tried from the bench to make changes but unfortunately it didn’t work out and we can’t say we were unlucky today, we were simply not good enough.
“There’s no point of being down or moaning now. We can’t doubt ourselves and tomorrow I want to see happy faces on the training ground, and very determined ones to know what we’ve done wrong today and to do everything to jump back on the winning track.”