Chelsea moved 13 points clear of nearest rivals Tottenham at the top of the Premier League as Gary Cahill struck a late winner after Jonathan Walters had cancelled out Willian's free-kick.
Costa was booked after going to ground too easily during an altercation with Stoke defender Bruno Martins Indi in the early stages, but kept a cool-head to stay on the field despite coming under provocation from several members of the home side.
Conte clearly feared Conte's emotions might cost Chelsea as he sent Michy Batshuayi out to warm up following official Anthony Taylor's decision to caution the striker.
But the Italian was delighted to see his player keep a lid on things.
"It is not simple to get a yellow card after a few minutes," said Conte.
"Diego is showing in all this season, not just this game, great discipline, great commitment. He showed me [his ability] to think for the team and not for himself and I want this from my players, this type of behaviour. He was great, he played a difficult game but he always showed danger for the defensive line for Stoke."
Asked if he felt it was part of Stoke's game-plan to unsettle Costa, Conte added: "I think that it's normal to try to bring a player to be angry and then to react and to commit another foul. It's normal, this.
"I think the great news is that Diego is showing [himself] to be a great player, also in this aspect.
"I know in the past sometimes he has received two yellow cards and not finished the game, but this season I have to be pleased for him and for his behaviour."