Spurs were 5-0 down within 21 minutes at St. James’ Park on Sunday in a humbling defeat that further derailed their bid for Champions League qualification next season.
Spurs chairman Daniel Levy said in a statement: “Sunday’s performance against Newcastle was wholly unacceptable. It was devastating to see. We can look at many reasons why it happened and whilst myself, the Board, the coaches and players must all take collective responsibility, ultimately the responsibility is mine.
“Cristian will leave his current role along with his coaching staff. Cristian stepped in at a difficult point in our season and I want to thank him for the professional manner in which he and his coaching staff have conducted themselves during such a challenging time. We wish him and his staff well.
“Ryan Mason will take over Head Coach duties with immediate effect. Ryan knows the Club and the players well. We shall update further on his coaching staff in due course.
“I met with the Player Committee today — the squad is determined to pull together to ensure the strongest possible finish to the season. We are all clear we need to deliver performances which earn your amazing support.”
Stellini took over at Spurs until the end of the season following the departure last month of Antonio Conte, for whom Stellini served as assistant coach.
Stellini took responsibility for Sunday’s defeat, noting his side were so badly beaten in the opening spell of the match.
“It went so badly because we were not prepared enough to play an important match. We have a good squad but today no one showed how good we are,” Stellini told Sky Sports after the match.
“It was my responsibility to decide how we play and we decided to do it differently because of the injuries. It is my responsibility, I took it and it was wrong. I have to take responsibility because once we changed system we played better, scored and showed fight. It’s very difficult to understand why the first 25 minutes were so bad.”