Patel, guest driver for Euro International team, went past teammate Hare on the penultimate lap to snatch the thrilling second race of the day at the Buddh International Circuit.
It was first international win in single-seater racing for the 25-year Patel, who hails from Chennai.
Hare, who triumphed in the first race of the day, claimed the three of the last four races to secure the championship and was followed by Nabil Jeffri and Afiq Ikhwan.
It was disappointing for both Jeffri and Ikhwan as their race ended early following a collision in the eighth lap.
"There was a lot of dicing going on in the front between Aston, Nabil and Afiq. I was right behind them just waiting for something to happen and then there was contact between Afiq and Nabil, which got me right behind Aston," Patel said.
"Down the back straight, I managed to slipstream and get by and from there I just looked in front and kept going," Patel added. More
