Fleming said MI played a "nice brand of cricket even in our conditions".
"They (MI) were confident, playing well and putting us under pressure. They were playing a nice brand of cricket even in our conditions...they have simply outplayed us," Fleming said at the post-match conference on Tuesday.
"They (MI) have got some players who are more suited to the conditions. They have a pretty good record in Chennai and adjust to the conditions. They are in form and have a nice, balanced side. It is a good challenge when you come up against a side like that it can always be 50-50," he added.
"It (pacing the innings) is tough. That is the problem we are finding, we are so far behind in powerplays. We are doing things right from overs 6 to 20, the run rate today I think was 7 and (then) 10 (in the last six overs). We're getting the right runs there, (but) we are just finding ourselves behind in powerplays," he said.
The New Zealander said the slow starts had not helped the side's cause and added a score of 40 or more in the powerplays would have helped.
"You run the risk if you over-attacked in the middle in those conditions, you can find yourself bowled out for 100. So you've got to have an element of safety. By the time you get that it's around 14 overs, from there we were able to go at 10 an over which got us through to a competitive score.
"But we need to have more balance in the first six overs -- around 40 would be nice. That may get you to a score of 150-160 which can be a match-winning score. We're just falling behind at different stages but it's the first six that's holding us back. Maybe we just throw the shackles off and have a crack in the next game and see if we can just get ourselves into form and confidence," Fleming said.