The win left the Super Kings unbeaten in four matches and consolidated its place atop the eight-team league, while Challengers suffered their third loss in four matches.
Earlier electing to bat first after winning the toss, Dhoni lifted the Chennai innings to a 178 for five, after the visitors made a slow start in the tournament after three impressive wins.
The local team made a spirited chase and looked poised for a win rattling 93 runs of the first ten overs. But there after its players virtually committed a 'hara-kiri' getting themselves dismissed due to lack of application.
Ross Tylor again played a pivotal role for Bangalore with an innings of 53 off just 34 balls which included three fours and three sixes. However he got out at a crucial juncture to leave Bangalore in a tight spot with the local team needing 56 runs from last five overs.
Test opener Wasim Jaffer seemed inspired from the hard hitting New Zealand batsman and hit a quickfire 50 in just 33 balls and when the two were at crease the Bangalore outfit was well on its way to a victory.
The departure of the two key batsmen, removed by puny Tamil Nadu medium pacer Palani Amarnath put the skids on the Challengers march.
The South African duo of Jacques Kallis and Mark Boucher, on whom the local team depended so much, could not do much today as both were dismissed cheaply forcing to raise the run rate.
Bruly medium pacer Manpreet Gony took three wickets, including that of rival skipper Rahul Dravid who made a second successive blob, to return most successful bowler for Chennai.
Earlier a belligerent Mahendra Singh Dhoni hit a whirlwind 65 off just 30 balls to power Chennai Super Kings to a competitive 178 for five in 20 overs., against Bangalore Royal Challengers, in the DLF-Indian Premier League T20 tie played at M Chinnaswamy stadium here today.
The Super Kings, who had three runaway wins in as many matches in the league so far, made a slow start for a change a, thanks to some purposeful bowling by Dale Stein, who made the IPL debut, and the duo of Zaheer Khan and Praveen Kumar.
But when Dhoni arrived in the middle, with team struggling at 83 for 3 in 12 overs, he made all the difference. In the able company of prolific Aussie batsman Michael Hussey, who hit a purposeful 47 off 37 balls, the Indian one-day captain lifted the Chennai innings with his swashbuckling knock. In the last two overs he scored 37 runs to take the visitors to a total which looked defendable.