Grant said: "I have only been in charge for three days. We had not won for three games and then we faced this difficult match. But, despite losing, I cannot fault the spirit of my players. We have good spirit and a good base.
Grant admitted it would have been better for him had he been able to replace Mourinho in the summer.
He said: "It would have been easier for me to have taken the team at the beginning of the season and prepared them.
"I accept how the supporters were. They had a great attachment with Jose and he did good things before me."
But Grant refused to accept they were slipping out of the title race.
"So why shouldn't we have a chance when it is five points?"