Marcus Rashford and Ander Herrera were on target as United secured a 2-0 win over the league leaders, which blew open the title race in the process.
Second-placed Tottenham trail Chelsea by just four points after the north Londoners comprehensively defeated Bournemouth 4-0 on Saturday afternoon.
Chelsea, who were without Thibaut Courtois and Marcos Alonso at Old Trafford, looked lacklustre against United and devoid of solutions as the hosts produced a scintillating attacking display while remaining defensively solid.
And Conte said after the game that United deserved to take all three points against Chelsea because the hosts demonstrated a greater desire to win than the visitors - and accepted the blame for the end result.
"They deserved to win, because they showed more desire than us, more motivation," he told Sky Sports.
"In this case, the fault is the coach. It is mine. In this case I wasn't able to do the right motivation.
"To play this type of game from now and until the end we must have great enthusiasm, great motivation to try to reach the target.
"This for us is a fantastic target."
He added: "I have concern because we have to work together and find quickly the right ambition to win this title - if someone thinks it's normal for Chelsea to win the title, we started as underdogs after 10th place last season.
"Tottenham is in good form and playing with enthusiasm, we must find the same."