The Mexican scored a late winner to down the Blues, who had Branislav Ivanovic and Fernando Torres sent off at Stamford Bridge, which allowed the Red Devils to go within a point of the league leaders.
Chicharito acknowledges just how big a win it was and suggests it could go a long way to helping them fight back to take out the Premier League title.
"This game could have changed the title," he told the Evening Standard.
"That's why it was important we didn't allow them to get ahead. It was vital to get the three points at a very tough place. We are in there in the fight to win [the Premier League]."