Zlatan Ibrahimovic has warned West Bromwich Albion about a growing confidence in the Manchester United dressing room.
The Swede scored the winner on Wednesday night as United saw off Crystal Palace 2-1 and extended their unbeaten run to nine games in all competitions.
United have been left frustrated by a series of draws in recent weeks after dominating matches, but have converted chances into six points against Tottenham and Palace since securing Europa League qualification against Zorya Luhansk last week.
And Zlatan believes the Baggies should beware an increase in swagger ahead of tomorrow evening's trip to the Hawthorns in the final match before Christmas.
He said: "We are working hard, we have confidence, we believe in what we are doing, we work very hard for it and we will keep focused like we are at the moment.
"We have always had the belief and we keep getting more confidence from these games.
"We have been disappointed in some games, so let's keep going like this and get the three points that we need to get closer to the top. When you win these games, they are the ones that give you a lot at the end of the season because it is not easy to play (at Selhurst Park).
"This was my first time. All of the guys said to me it would be a very difficult game and that was what it was.
"It was going through my head, another draw where we are up 1-0 and they get 1-1. But we got the winning goal and that is the most important thing. Now we have closed the gap (on Arsenal following their defeat to Everton) even more and we have to keep like this."
Meanwhile, West Brom boss Tony Pulis hailed Salomon Rondon after the £12million striker's hat-trick beat Swansea on Wednesday night.
The Venezuelan scored his first treble in the Premier League with three headers in 13 second-half minutes to seal a 3-1 win.
It lifted the Baggies to seventh as they continued a surprise bid to reach Europe having won four of their last six games - scoring 10 goals in three home matches in the process. Rondon now has seven goals for the season, after netting 10 last term following his move from Zenit St Petersburg, and Pulis believes he can still improve.
He said: "He's getting better and he's scoring goals. He finds it very difficult at times to understand how hard every game is, but that comes with time.
"He was up and down last year but he's been more consistent this year.
"The great thing about tonight is that he missed two great chances in the first half and it hasn't affected him. We had to grind it out. The first half was scrappy, but Salomon still missed two chances without us playing well. The 20 minutes after half-time was more like us and obviously he scored a wonderful hat-trick."