It was Suresh Raina who struck a fighting 59 off 37 balls to prepare the road for revival following a slow start and Dhoni (unbeaten 44 off 22) provided the late flourish, ending the innings in style with two sixes off Trent Boult.
After making just 27 runs in Powerplay overs, the hosts eventually put on board a fighting 179 for four and dismissed Capitals for just 99 in 16.2 over to snatch the top spot from the visitors.
Capitals suffered a surprise batting collapse after being consistent this season. They were out of the game after losing half the batsmen by 11th over and ended up suffering their worst defeat. It was also their lowest total of the season.
CSK, who now sit atop the table with 18 points, are now sure to end in top-2, ensuring that they will have two shots at making the summit clash.
South African spinner Imran Tahir (4/12) and Ravindra Jadeja (3/9) tore apart the middle order, sharing seven wickets between them.
Dhoni's quick hands were at it again as he affected two lightning fast stumpings, to dismiss skipper Shreyas Iyer (44) and dangerous Chris Morris (0).
Except Iyer and Shikhar Dhawan (19) none of the other Delhi batsmen could reach double-digit mark.