Shikhar Dhawan scored an 85-ball century, the fastest by any cricketer in Test history to lead India to 156 for no loss at tea, trailing Australia (408) by 252 runs in Mohali on Day 3 of the third Test. File Photo: Shikhar Dhawan during the Ranji Trophy. The 27-year-old hit a staggering 21 boundaries to dispel doubters, who questioned the decision of replacing Virender Sehwag. West Indies? Dwayne Smith held the previous record of the fastest century debut for his 93-ball hundred against South Africa in 2004. Former Australian cricketer Richie Benaud tweeted: Once again, with Shewag being replaced by a better, younger model, the Law of Natural Selection is proven true. #Dhawanism #INDvAUS — Richie Benaud (@RichieBenaud_) March 16, 2013 Shewag was dropped for the third Test after a poor showing in the opening two Test matches. India lead the four match Test series two-nil. Dhawan was arguably excited about the news: ?I was very happy to hear the news,? Dhawan said. ?I just want to grab this opportunity. Of course I was waiting for this day, but I don?t have any pressure right now. I am happy that whatever I dreamt of achieving, I have done that.?