Louis van Gaal admitted Manchester United only have themselves to blame after West Brom claimed a smash-and-grab 1-0 win at Old Trafford on Saturday.
Jonas Olsson's fortuitous deflection off Chris Brunt's free-kick around the hour mark condemned United to a third straight Premier League defeat for the first time since 2001, with Van Gaal's miserable day compounded when Robin van Persie missed the chance to equalise from the penalty spot 18 minutes from time.
United dominated the contest from start to finish but, as was the case in their recent losses at Chelsea and Everton, failed to make their possession count.
And while insisting his side were unlucky to lose, Van Gaal said West Brom's backs-to-the-wall approach came as no surprise.
"We knew in advance they would park the bus and we have to deal with that," the Dutchman told Sky Sports.
"I think in the first half we didn't create enough, but in the second we had enough [chances] to score.
"[That is] now the third match in a row [where United have lost while failing to score]. You are attacking all match, but it is very disappointing when you are not scoring.
"The finishing was not good enough. I've seen a team that fights until the end, that attacks for 90 minutes, and one free-kick is enough to beat us.
"We were a little bit unlucky, but that is not enough.
"The players are disappointed, I am also disappointed."
