The 21-year-old returned to the crease with Matt Prior after a solid start on day one and hit 73 to help England eventually reach a first innings score of 330 all out.
James Anderson made an early breakthrough as he ousted Virender Sehwag for a duck before also taking the scalps of Sachin Tendulkar (2) and Gautam Gambhir (37).
Off-spinner Graeme Swann dismissed Chesteshwar Pujara, with India finishing day two on 87-4, 243 runs behind the tourists.
“It’s not an easy pitch to score on and they set very, at times, defensive fields so you had to be very patient and be very selective of the areas you were going to score,” Root told Sky Sports.
“I just tried to wait and be as patient as possible and be really disciplined and grind it out.”
Root reserved special praise for Kevin Pietersen (73), Matt Prior and Swann, who all contributed significant runs to help England reach a credible score.
“Kevin’s knock was fantastic and so was Matty’s, and Swanny’s was very vital so we’ve got ourselves in a decent position,” added Root.
“It was a great spell of bowling [from Anderson]. He’s been brilliant throughout the series as he has been for the last three years. Hopefully he can come out tomorrow and get a few more.”
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BIOGRAPHY: Cesc Fabregas