The Short Version
This claim is wrong on two independent counts. India's first-ever Test cricket victory occurred on February 10, 1952, against England at Chepauk, Madras — nearly two decades before 1971. The 1971 milestone was India's first Test win *in England*, not its first-ever Test win globally. Additionally, even that 1971 achievement took place on August 24, 1971, at The Oval — not on April 20 as stated. No credible source supports either the date or the "first-ever" framing.