Fast runner passed rival (7)
I believe the answer is:
emulate
'rival' is the definition.
(I've seen this before)
'fast runner passed' is the wordplay.
'fast runner' becomes 'emu' (bird known for its distinctive run).
'passed' becomes 'late' (I can't justify this - if you can you should give a lot more credence to this answer).
'emu'+'late'='EMULATE'
Can you help me to learn more?
(Other definitions for emulate that I've seen before include "ambitious veteran" , "Copy -- reach equality with" , "Try to equal by imitation" , "Strive to equal or match" , "Model oneself on" .)