John Campbell blazed a 65‑ball century at Barsapara, snatching a 1‑0 lead for the West Indies.
He smashed nine fours and five sixes, smashing the field, and reached his hundred in the 17th over off Kuldeep Yadav.
His record‑breaking knock eclipses Chris Gayle's fastest 50 and 100s, making him the quickest West Indian to score a century against India.
India will look to regroup for the final match while the West Indies tighten their chase tactics.
The third and final ODI will take place at the same venue on Thursday, with each side fighting for the series.