Agreed to be taken out of ringside seat? That's it - I kid you not! (6)
I believe the answer is:
insist
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for insist that I've seen before include "Demand forcefully" , "Take no refusal" , "Be adamant" , "Maintain strongly" , "Be firm in demands" .)