The nation, the world's third-most infected, on Sunday reported 78,761 new cases in 24 hours, passing the number posted in the US on 17 July.
The rise comes as the government continues to lift restrictions to try to boost an economy that lost millions of jobs when the virus hit in March.
An upsurge of Covid-19 in many rural areas continues to be a major concern.
On Sunday, global infections passed the 25 million mark, with 843,000 deaths. The US remains the most affected nation, closing in on six million infections, according to Johns Hopkins University research.
What's behind the Indian increase?
India's single-day tally on Sunday passed the one-day increase of 77,299 reported by the United States on 17 July.
Cardiology doctor, Manoj Kumar, told Reuters: "It is the largest one-day surge in cases worldwide and the reason behind this - because the pandemic is spreading in the rural areas."
In the initial stages of Covid-19, India appeared to be doing fairly well, imposing a strict lockdown, but the virus then hit megacities like Mumbai and Delhi, before surging in smaller cities and rural areas.
Despite the increase, the government has pressed ahead with easing restrictions.
Gatherings of up to 100 people will be allowed at cultural, entertainment and sports events from next month, with face mask and social distancing measures.
Underground train networks will also start to reopen in big cities.