The Super Kings are well-placed to reach the Champions League Twenty20 semi-finals after their 13-run win over the Scorchers in Bangalore on Saturday.
Ravindra Jadeja (44 not out) and Dhoni (35 off 16) set up Chennai's total of 155-6, and the Scorchers - who were knocked out as a result of their defeat - fell short in pursuit.
Dhoni said it was an improved display from his team, but he is still demanding more in the latter stages of the tournament.
"We made a mistake," he said.
"Our intent was good, we went with a positive attitude, but we needed to assess the pitch. We went too hard at the ball.
"After that [Mithun] Manhas and [Dwayne] Bravo gave us a crucial partnership. Jadeja's hitting, the way he went after [Brad] Hogg who was tough to hit, was very crucial. His innings changed the course of the match.
"We improved today, but we lacked in the batting. We didn't adapt to the wicket, and play for what the par score here is. The bowling performance was fantastic."
Scorchers captain Adam Voges lamented the way the game got away from his team, who had the Super Kings struggling at 79-5 in the 15th over.
Voges praised Hogg (1-25), but said it was Dhoni and Jadeja who won the game for the Super Kings.
"Last three overs of their batting innings, Dhoni and Jadeja took the game away from us," he said.
"We bowled really well until that point, but they were unbelievable, and we ended up chasing 20-30 more than we should have. Hoggy bowled beautifully, as did the others, but Dhoni did what he does best."