Martyn scored his first century, about 9 years after making his debut, in The Ashes, against England on 5 July 2001 at Edgbaston Cricket Ground, Birmingham scoring 105 runs in the process. His performance in the series earned him the Wisden cricketer of the year award for 2001. His highest score of 165 runs came against New Zealand on 18 March 2005 at Basin Reserve, Wellington. His last Test century was against South Africa on 31 March 2006 at The Wanderers Stadium, Johannesburg where he scored 101 runs. Out of his 13 Test centuries, 8 has been scored on the first innings and the rest 5 in the second innings.