West Brom Tony Pulis said he "went mad" at his players for checking scores on a phone before their 1-0 win at Manchester United.
Earlier in the day relegation rivals Leicester City, Aston Villa and Sunderland had all won their games.
But Albion reached the 40-point mark with victory at Old Trafford.
"I thought that someone had their phone on in the dressing room before kick-off and I went mad with them," Pulis told Match of the Day.
"So to win and then find out what the results were and realise everyone had done well, it just highlights how important it is to get to those 40 points.
|United's three-game slump|
|Manchester United have lost three Premier League games in a row for the first time since December 2001.|
|The last time Manchester United failed to score in three successive games was between May and August 2007.|
"I try not to listen to the results when there are games going on that could affect you. No-one comes near me because if they do I go berserk."
Any concerns the Baggies had about being dragged towards the relegation zone were eased by Jonas Olsson's fortuitous goal against United.
The Swede unintentionally deflected Chris Brunt's free-kick past David De Gea, before Robin van Persie had a penalty saved by Albion keeper Boaz Myhill.
It meant United suffered a third consecutive loss in the league, following defeats by Chelsea and Everton.
And it puts Louis van Gaal's side's hopes of claiming the fourth and final Champions League qualifying spot in jeopardy, with Liverpool closing the gap on the Red Devils to four points with a 2-1 win over QPR.
"Maybe you all remember my press conferences where I said it will be a rat race until the very end," said Van Gaal.
"I was the only one because we were seven points ahead at the time.
"But I said it was still possible to be caught. I'm aware of that and my players shall be aware of that."