"Definitely, it has put us in driver's seat and it's not just the amount of runs but at what pace those runs have come has made the huge difference," said Agarwal, who got to his second successive Test hundred on the opening day.
Indian pacers have already reduced the Proteas to 36 for three at stumps on the second day.
"The double hundred has given the team extra session and half, which becomes very crucial. The partnership between Virat and Jadeja was fabulous and almost at run a-ball 230-odd (225), which is fabulous. If you are looking to win games, then you want to have that time to get 20 wickets," said the Karnataka right-hander.
"To get a 250, it's no joke and way he is batting is tremendous. The positivity and intent is fabulous. The records and his scores, prove everything that we all need to see (learn)."