Tony Pulis believes his West Brom side got the luck any team needs if they are to come away from Old Trafford with all three points in Saturday's 1-0 victory.
West Brom condemned Manchester United to a third straight Premier League defeat thanks to Chris Brunt's free-kick on the hour, which took a wicked deflection off Jonas Olsson to beat David de Gea.
And Pulis admitted the visitors - who also won at Old Trafford last season - were slightly fortuitous to escape with a victory that all-but secures their top-flight status for another year.
"To come here, you have to be resilient, you have to be well set-up," said the head coach.
"We worked very hard this week to make sure people were in the right spots to stop United from penetrating.
"You still need a bit of luck and we had that - we had the run of the ball.
"Beating United at Old Trafford is brilliant and something the players will take on board. It's a great three points [but] now we move on. We've got three very tough games left.
"The fact 50-60 per cent of the players in the team came here and won last year certainly gave us a psychological edge."
Referee Anthony Taylor pointed to the spot after Saido Berahino blocked Antonio Valencia's cross with his arm, even though the official's assistant gave a corner.
"It wasn't a penalty, that was very disappointing. It was a yard outside the box," Pulis added.
