The win came despite a career-best 129 from Salman Butt for Pakistan as they unsuccessfully chased India's 294 for six.
Left-handed batsman Yuvraj Singh underlined his form with a neatly paced 77 for the Indians before Pakistan were bowled out for 248 in 47.2 overs on a slow turning track.
Butt, 23, made a valiant bid after reaching his fourth one-day hundred - all against India - after Pakistan lost the explosive Shahid Afridi (12), who returned as opener, and Younis Khan (21), who hit a match-winning 117 in the last game.
The left-handed batsman was ninth out, ending a 142-ball effort studded with 17 fours. Pakistan had chosen to bowl.
Yuvraj raised 100 runs from 92 balls with skipper Mahendra Dhoni (49) and both attacked the inconsistent Pakistani bowling after Saurav Ganguly (39), dropped first ball, and Sachin Tendulkar (29) added a breezy 68 runs for the first wicket.
The fourth match will be played in Gwalior on Thursday.