The AC Milan midfielder was followed by his teammates in abandoning the friendly game in Busto Arsizio on January 3.
"It is wonderful, I appreciated it enormously," Platini told French radio station RTL.
"It was excellent, in fact I later called Milan to congratulate them."
However, Platini added that during Champions League and Europa League matches, it is the referees who will have the decision to call off a game if there are any racist chants from the supporters.
"We implemented rules for Champions League and Europa League matches for the referees to follow," he said.
"If they hear racist chants, there is an appeal for them to desist over the public address system and the match is stopped for a minute. After that if the chanting resumes there is a stoppage of two minutes and a new appeal for them to stop.
"A third time and the referee can call the match off. It is the referee who is the boss in the stadium."
Platini has been the UEFA president since 2007.