England skipper Joe Root on Friday became the ninth batsman to slam a century in his 100th Test, on Day One of the first Test against India here at the MA Chidambaram Stadium. It was the 10th instance of this feat occurring as former Australia captain Ricky Ponting is the only batsman to score centuries in both innings of his 100th Test, against South Africa in 2006.Root brought up his 20th century off 164 balls, with the help of 12 boundaries. This was his third century in as many Tests, with earlier two coming in Sri Lanka in the previous series that England won 2-0, just before the team reached India for this series.Root also became only the third cricketer to play both his first and 100th Test match in the same country he was touring. Root had made his debut in Nagpur in 2012 when England won the series 2-1. Friday's ton was his fifth one against India in 17 matches.West Indies' Karl Hooper and India's Kapil Dev are the two others cricketers to make their Test debut and play their 100th Test in the same country. While Kapil made his debut (1978) and played his 100th Test (1989) in Pakistan, Hooper achieved that milestone in India (1987 and 2002).Colin Cowdrey (104 vs Australia in 1968), Javed Miandad (145 vs India in 1969), Gordon Greenidge (149 vs England in 1990), Alec Stewart (105 vs West Indies in 2000), Inzamam-ul-haq (184 vs India in 2004), Ricky Ponting (120 and 143 not out vs South Africa in 2006), Graeme Smith (131 vs England in 2012) and Hashim Amla (134 vs Sri Lanka in 2017) have earlier scored centuries in their 100th Test.