Succeeding like a slope-producer (6,3,5)

'succeeding' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'a slope-producer' is the wordplay.
I cannot really understand how this works, but
'a' is found in the answer.
'slope' could be 'grade' (I've seen this in another clue) and 'grade' is found within the answer.
This may be the basis of the clue (or it may be nonsense).

'like' acts as a link.

Can you help me to learn more?