Spurs had the lead through Dominic Solanke before Micky van de Ven gave away a penalty and was sent off four minutes later. Ismaila Sarr converted from the spot, then Jorge Strand Larsen struck before Sarr hit a second before halftime for the 3-1 win.
The result leaves Spurs just one point above the dropzone.
Afterwards, Tudor said: : "It was two games. After the red card, it was a second game. The second half we tried and I saw interesting things but I'm very disappointed like the fans.
"We need to work hard and believe. After this game, I believe more than I did before. I know that sounds strange but I saw something in the team. Even in the dressing room after the game. When we are complete, and choose the right guys, I believe it will be good."
On fans leaving the stadium at halftime, Tudor said: "Of course I understand the fans. It’s a normal thing that happens in football. They are disappointed. They wanted more. We are aware of that. We also wanted to give more. Unfortunately this is the moment that we pay everything. One red card changes everything.
"I will tell you now maybe it will sound strange but I believe more after this game than I believed before. I saw something. I need to choose the right guys because the boat is going in the direction that I want to go and needs to go and who is in the boat can stay.
"Otherwise they can leave the boat. So when the other players will come back and choosing the right (players) I’m sure we will have a good team and the victories will come back. It’s not easy to accept the moment where we are now but it is how it is."