Sri Lanka faltered in their chase right from the start losing wickets at regular intervals before getting all out for 274 in 45.4 overs.
Lahiru Thirimanne scored 77 runs, while Jeevan Mendis tried to play an anchor's role, scoring 72, but ran out of partners and was eventually caught behind.
Irfan Pathan was on target as he clinched five wickets.
Irfan was declared as the man of the match for his five wicket haul and 28 runs with the bat.
Vice captain Virat Kohli, who scored 296 runs at the average of 74, was adjudged the man of the series.