Conte says he is worried that Spurs, who have now won six on the bounce, now have the momentum in the run-in and could inflict further psychological damage on his side by beating them in their FA Cup semi-final at Wembley on Saturday.
He said: “It won’t be easy because Tottenham are now the best team. They are in good form and playing with enthusiasm – we must find the same.
“They are feeling the possibility to write history and it is important to know this.
“I have concern because we have to work together and quickly find the right ambition to win this title. If someone thinks it’s normal for Chelsea to win the title, they must remember we started as underdogs after 10th place last season.”
United manager Jose Mourinho was relieved to gain a win that keeps their top-four hopes alive.
“The satisfaction is for different reasons,” he said.
“After Liverpool and Manchester City’s victories, if we didn’t win then goodbye top four. And when you beat the leaders it is obviously a very good feeling.”
Rashford, scorer of United’s first goal, said: “It was a clever pass from Ander Herrera, we made eye contact and he put the ball exactly where I want it. It’s something we need in this team.”