Chadli and Kane were arguably the two best players on the pitch at White Hart Lane, as Spurs stunned their London rivals 5-3 in the Premier League on New Year’s Day.
"I think we made some defensive mistakes, some individual defensive mistakes,” Mourinho told BT Sport. “It was not easy for my defenders to cope with Nacer Chadli and Harry Kane.
“It was also very difficult for Tottenham defenders to deal with an amazing Eden Hazard and good Diego Costa. You can speak about crucial moments of the game but I prefer to focus on the result.
“The players tried a lot but the fifth goal killed a bit our fantastic reaction. We had important Christmas gifts in the last two matches, Christmas gifts that people who love football do not like.”
Tottenham are currently fifth in the Premier League table, while Chelsea are level on points with Manchester City at the top of the standings.