Clue: Great Asian captain's claim to being eighth in line and not third (5,4)
Answer: IMRAN KHAN
Explanation: Definition: Great Asian captain
A charade of I'M RANK H ('claim to be eighth in line' with the preceding words doubling as definition and justification for the grammatical form) plus 'an[d]' minus its third letter ('and not third'). Among 's many achievements, Enigmatist cites his captaincy of the Pakistan cricket team.