Manchester City have moved up to third spot in the English Premier League title race while Tottenham slumped to a draw with Fulham leaving them down in sixth.
“In the first half (Fulham goalkeeper) Alphonse Areola made some impossible saves, a couple of others in the second too,” Mourinho said.
“We have to kill a game and we didn’t - but you have to keep a clean sheet, not make mistakes, so it was a very avoidable goal.
“The markers are there, there wasn’t even an advantage in terms of numbers.
“We have bad results and we should - and we could have - avoided these results.”
Meanwhile, Manchester City’s 1-0 win over Brighton & Hove Albion makes it four wins in a row for Pep Guardiola’s side who are back in contention.
Phil Foden netted a 44th minute near post winner from Kevin De Bruyne’s pass, while Raheem Sterling missed a stoppage-time penalty for City.
Guardiola heaped praise on Foden. “I said many times what I think about Phil - the number of games goals, assists and kilometers he runs for the team,” Guardiola said.
“Hes a guy close to the goals he has a special instinct - his standards are higher and he deserves to play.
“I try to judge the team day by day; recent performances and he lives 24 hours for football. I have the feeling he lives 24 hours a day to play football.”