Balotelli opened the scoring as City ran out 3-0 winners in a one-sided contest at the Etihad Stadium to move five points clear at the top of the Barclays Premier League. The maverick Italian striker was making his first league appearance for a month after serving a four-match domestic ban for stamping on Tottenham's Scott Parker.
Platt said: "I actually thought he was very disciplined in his performance and his work rate was exceptional both on and off the ball. His temperament was good. He can be pleased with his afternoon's work."
Manager Roberto Mancini has said he wants full concentration from the 21-year-old in the title run-in and Platt believes there were plenty of signs of that.
Platt was also pleased with the way Balotelli dealt with his treatment from the Blackburn defence.
He said: "When a team defends deep against you like that, and to open them up you have got to give the ball to people who are marked and closely guarded, there are going to be kicks like that. But you never once felt there was going to be any reaction today."
Balotelli celebrated his goal by revealing a T-shirt bearing a message of love for his girlfriend Raffaella. It was a rather more modest offering than a previous one of 'Why Always Me?', referring to his notorious off-field antics earlier this season.
Platt said: "All players flash T-shirts nowadays. There are a lot of players that want to take their shirts off and show messages. I don't think it is a case of flamboyance."
Balotelli's strike gave City a 1-0 half-time lead which might have been greater but for a string of superb saves by Paul Robinson.
Sergio Aguero added the second earlier in the second half before Edin Dzeko came off the bench to head a third late on.