I didn't underestimated CSK, most who watched the batting of RCB could've had the same feelings of mine.
Yes, with the scoring in much faster manner this is all unexpected. RCB reached 100 runs in 50 balls, and 150 runs in 80 balls. Further the team missed the momentum as the wickets of du Plessis and Maxwell fell. Even after that Dinesh Karthik made his contribution. Somehow this is the Dhoni's luck that brought him the win.
You can love or hate Mahendra Singh Dhoni. But you can't deny the fact that he is the best captain out of all during this season of the Indian Premier League. It was his tactics which brought the victory to Chennai Super Kings. And trust me, it was not an easy task to defend the target against star batsmen such as Virat Kohli, Faf du Plessis and Glenn Maxwell. They are some of the best in T20 format. And on the other hand, CSK had some inexperienced bowlers, in the form of Akash Singh, Tushar Deshpande and Matheesha Pathirana. Without MSD, they would have lost the match yesterday.
For me Mahendra Singh Dhoni is GOAT of Indian cricket while he was playing for India his achievements are amazing with CSK is surely having one of the best captain ever and in near future we have no player with mindset like this in Indian cricket even now he is 40+ but still doing amazing job as captain and as batsman which is helping CSK for having good results just because of him now they are at 3rd spot in IPL league table which is not easy in presence of few toughest teams with quality players.
As they won last game now I am turning my views about them as top four spot is possible because they can handle pressure and this is important for the win in these matches, and they can bring positive results.