The victory parade of close to six kilometres saw the Mumbai Indians players sharing their joy with the fans who are an integral part of the MI family.
Chasing a modest 150 for victory, Watson, who was dropped on 56 by Rahul Chahar, carried Chennai's hopes with a belligerent 80 off 59 balls, his innings laced with eight fours and four sixes.
But once he was run out off the fourth ball of the final over, it was Sri Lankan Malinga who showed his class to snatch the crown from the defending champions.
In the last five overs, Chennai needed 62 off 30. Watson then hit Malinga for a hattrick of fours to trim the equation to 42 off 24 balls.
There was no stopping the veteran Australian, who scored a hundred to help Chennai win the IPL last time, as he clobbered Krunal Pandya for three back-to-back sixes in the 18th over which cost Mumbai 20 runs. But it wasn't to be Chennai's night this time around.