Left-handed Dhawan and right-handed Dhoni combined forces in splendid fashion after a cautious start to rattle up runs at over 7 an over and made light of the stiff asking rate of 5.52 set by India 'B' who had piled up 275 all out in 50 overs after choosing to bat first.
Chasing India B's score of 275, made mainly with the help of fine half centuries by Venkata Sai Laxman (67) and Sridharan Sriram (52), India Seniors achieved the target in only 46.4 overs and kept their hopes alive of entering the final on February 10.
Sourav Ganguly-led India seniors had lost the opening clash to India A, led by Rahul Dravid, by four wickets last night.
Dhawan compiled a stroke-filled 126 in 124 balls and studded with 16 fours and 2 sixes. But it was the 23-year-old Ranchi-born Dhoni who set the Wankhede Stadium alight with his audacious stroke-play in making a rapid-fire 87 off 76 balls before retiring to the pavilion with a bout of leg cramps.
He later came back to replace Ganguly when the latter got out for 27 when the score was 246 and then remained unbeaten till the end with a swashbuckling knock of 102 that included 10 fours and 4 sixes and came of only 96 balls. Fittingly he struck the winning hit too, a boundary, and also completed his century.
In the period before retiring to get some treatment for cramps, the wicket-keeper batsman had lit up the stands and entertained the 5000-strong crowd with punishing strokes, quite a few of them unorthodox like the flat-batted swats.
Dhoni clouted four sixes, all of them off the meat of the blade and two of them with superbly timed hook shots.
He lofted off break bowler Ramesh Powar for two huge sixes over the straight field and then hooked Joginder Sharma and Ashish Nehra for a six each over the long leg fence when they tried to bounce him out.
Dhawan and Dhoni, who was out first ball to Zaheer Khan yesterday and was understandably cautious initially, put on only 10 runs in the first five overs before opening out. The pair rattled up 77 runs between the 9th and 15th overs.
The medium pacer to get the rough end of the stick was Joginder Sharma who was carted around for 63 overs in his first 6 overs. Off break bowler Ramesh Powar was slammed for 34 in 23 balls in his first spell while Rohan Gavaskar gave away 19 in two overs as the opening pair simply waded into the India B attack.
Ganguly joined Dhawan when Dhoni retired and the tempo slowed down but India seniors asking rate had climbed down so much that they still could win on a canter.
Earlier, Laxman and Sriram batted in contrasting styles and put on 96 runs for the third wicket to help India B pile up a big total on a perfect batting wicket.
Laxman batted in his patented fashion, driving wristily and elegantly into the 'V' to make a fine 67 off 69 balls, embellished by 9 fours and a six, before being run out. The six was struck off left-arm spinner Rajesh Pawar.