Thomas was named as captain for Wales' final match in the 2007 Six Nations against England after current captain Stephen Jones was ruled out with a broken wrist. When Thomas took the field, he equalled Gareth Llewellyn's Wales record of 92 caps. He broke Llewellyn's record when he led Wales out against Australia at Telstra Stadium in Sydney on 26 May 2007, a match that Wales lost 29–23 on a Wallabies try after the siren.