In the repeat final, Mumbai, who beat Tamil Nadu by 141runs last year, annexed the trophy, the symbol of supremacy in domestic cricket, for the 36th time in their 39 appearances in the title clash.
Mumbai, by virtue of their first innings lead, were declared the winners.
Badrinath and Badani, who came together with Tamil Nadu at 180 for 4 and still needing 139 runs to avoid an innings defeat after losing overnight batsman S Ramesh (36) in the fifth over of the day, put up a spirited performance adding 173 runs for the unbroken fifth wicket in 85.1 overs.
Mumbai had assured themselves of the trophy on Monday itself after taking a huge 319-run first innings lead, making 613 in reply to Tamil Nadu's 294.
Tamil Nadu, who failed to make use of the flat batting track in the first innings, had to be content with the runner-up place for the eighth time in their 10 attempts.
Even as Mumbai went all out for a win, Badrinath (338b, 410m, 17x4) batted patiently, hitting his third Ranji century of the season to compensate for his duck in the first essay.
Badani (230b, 349m, 7x4, 1x6), who survived four confident appeals for caught behind, kept his cool as the duo dominated the Mumbai bowling.
Realising the importance of their stand, Badrinath and Badani played with utmost caution, resorting to defensive tactics, particularly in the first session after medium pacer Munaf Patel sent back Ramesh in his third over of the day, frustrating the Mumbai bowlers.
However, once the new ball was taken shortly before lunch, they launched into the offensive, scoring runs freely.
The highlight of the post-lunch session was the 100-run partnership and Badrinath crossing his half-century.
The script remained the same even after the tea break, with no success for Mumbai bowlers and the batsmen adding 70 runs as Badani reached his 50 off 159 balls.
Tamil Nadu wiped out the first innings deficit 30 minutes after tea with Badrinath on 97 and Badani on 57. Badrinath took his own time to reach his century as he faced 37 balls to score the three runs. A cracking square-cut off Bhavin Thakkar saw him reach the deserving three-figure mark.
Jubilant Mumbai captain Sairaj Bahutule, who received the trophy from Board of control for Cricket in India (BCCI) secretary S K Nair, credited the win to team effort. "I am very happy. The last two years have been good to us. It was a good team effort and I am honoured to be the captain of the side," he said.
Rival captain S Suresh admitted his side did not use the chance after winning the toss to put up a good total. "Coming so far and to lose in the final and that too at home really hurts. But, we have learnt a lot from Mumbai and this match."
In an instant honour for the champions, Mumbai Cricket Association (MCA) secretary Lalchand Rajput announced a bonus of Rs four lakh to the team that won the trophy despite the absence of star players Ajit Agarkar and Ramesh Powar who are with the Indian team in Pakistan.