Coach Maresca praises Chelsea's spirit in Forest draw after rash of yellow cards
Forest midfielder James Ward-Prowse was also sent off in the 78th minute for a second yellow card after two professional fouls, stopping first Cole Palmer and then Nicolas Jackson running free on goal.
The visitors' Portuguese coach Nuno Espirito Santo was also cautioned as tempers flared.
But Chelsea players received six yellow cards and could be fined by the Premier League for indiscipline. They have already received a fine this season after collecting bookings against Bournemouth last month.
Maresca said discipline was something his side needed to improve but added: "I like the team the way they are fighting for each other and becoming a team."
He added that he saw no problem in the players showing emotion. "I like the spirit of our team," he said.
The game started slowly before second-half goals by Forest's Chris Wood and Chelsea's Noni Madueke sparked it into life.
There were a host of opportunities at both ends and late in the game substitute Neco Williams's tackle on Chelsea's Marc Cucurella sent the Spain fullback sprawling into the technical area where he upended his own coach.
Several players then piled into a melee, including some off the bench, pushing and shoving each other before referee Chris Kavanagh regained control.
Chelsea enjoyed 66% possession and had 46 touches to Forest's 21 in the opposition box but failed to take their chances and could have fallen behind in the final minutes but for some fine saves from Robert Sanchez.
"At the end, it was an end-to-end game. Both goalkeepers got called into a lot of action," Sanchez said.
"For me and (Forest's Matz) Sels this is what's difficult about being a goalkeeper, you don't do much in the whole game, then minute 80 you have two big shots to save."
The draw kept Chelsea in fourth but three points behind Manchester City and Arsenal and four off leaders Liverpool.