Patrice Evra believes Manchester United must stop surrendering leads if they are to win the Premier League title.
United conceded two late goals to draw 3-3 with Everton a week ago, having also dropped points from a winning position against Fulham earlier in the season.
Liverpool were also allowed to claw themselves back level in Sunday's clash at Old Trafford, before Dimitar Berbatov completed his hat-trick to seal a 3-2 success.
The result keeps United within four points of leaders Chelsea but Evra is adamant that lessons have to be learnt.
"If we keep bringing that nervousness to the situation we could finish the game with a heart attack," said the left-back.
"It wasn't that I was worried at 2-2. I was actually very unhappy.
"If we had drawn that game, how could we then say we were going to win the league.
"We had an accident at Fulham. We had another accident at Everton. But if you do it again it is not an accident. It is simply that you do not want to win the league."
Evra does not feel the blame lies solely with the back four, as many of the goals United have let in this season have come from crosses and set-pieces.
"I don't know why we make the job hard when it could be so easy," he admitted.
"We have to make sure that kind of thing doesn't happen again. We need to make Manchester United solid.
"It is not only about the defenders. It is about everyone.
"We conceded two goals in a match where the opposition didn't even have a shot on target. That type of thing should not happen."
One major positive from the start of the campaign has been the form of Berbatov, who has scored six Premier League goals.
The Bulgarian has sometimes frustrated supporters in the past but Evra maintains that he has always been a popular figure in the dressing room.
And speaking about Berbatov's magnificent overhead kick against Liverpool, Evra said: "He scores a lot of goals like that in training. I am not surprised.
"He can do so many things and I hope and wish he will carry on that way for the rest of the season."
Evra added: "Dimitar deserves this because everyone knows he has such a big talent.
"I have never been worried about his form, but he has had a hard time here.
"It has never been easy but he has continued to work very hard.
"It is not only against Liverpool that he has done well. It has been from the beginning of the season.
"He has everything in his game to be the best striker here. I am really happy for him."