Mauricio Pochettino believes Tottenham have shaken off their reputation as a soft touch, but acknowledged his players overstepped the mark in the fractious draw at Chelsea.
Monday's encounter at Stamford Bridge was packed with incident as a 2-2 draw ended Spurs' Premier League title hopes.
The visitors had nine men booked and on Friday Mousa Dembele accepted a Football Association violent conduct charge, which looks set to land the Belgium midfielder a lengthy ban.
But boss Pochettino put a different spin on his players' overtly aggressive approach.
"I have heard in the last two years that people have written that Tottenham were always soft, something like that, but now we start to show character," he said ahead of Sunday's visit of Southampton.
"This season we have shown we are not a nice team to play. Not anymore. We show passion, maybe too much passion, but we need to take this in a positive way.
"This season we created very good energy between fans, staff, players, and we need to manage better to try to win the title.
"Maybe we crossed the line [on Monday]. I am not stupid. I can recognise that. If you want to win titles and keep your position for a long time, in the future you need to show passion.
"I can understand my players, I can understand my staff. We have shown enough character and quality to be contenders for the Premier League."