Chasing 241 for victory, the visitors achieved the target with two overs to spare losing four wickets in the process.
Pakistan thus levelled the series 1-1 after they lost the opening encounter at Sirsa on Monday.
Akhtar's innings of 100 consisted of eight fours and a six and came of only 89 deliveries. Azeem Khan with an unbeaten 52 and Ashraf Pakhali (31) gave him good support.
For India, Atul Wassan claimed two early wickets but it was not enough.
Akhtar added 56 for the third wicket with Pakhali and then 52 with captain Rashid Latif. Earlier, opener Atu Wassan (58) and former India captain Mohammad Azharuddin (45) added 92 runs for the second wicket to take the Indian score to 240 for nine in 40 overs.
Sameer Dighe contributed 33 while Syed Kirmani was 22 not out. Vivek Razdan hit some lusty blows towards the end in his 19.