Wholehearted, matador's opponent came in a rush, employing twisted openings (4-7)
I believe the answer is:
full-blooded
'wholehearted' is the definition.
(both can mean sincere or determined)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for full-blooded that I've seen before include "Wholehearted, vigorous" , "Without compromise" .)