I’ve had this experience many times — people will
    internalise their limitations and assume that their 
    best is the best possible. Etc..

The closest I've come to a winning formula here is to

1. Build a relationship where you have given praise and positive feedback to the individual's other efforts, privately and publicly. To be 100% clear here I'm talking legitimate praise here, not butt-kissing.

2. Find a way for the "victim" to share in your achievement somehow. Help him save face. "Bob and I were looking at ways to optimize the batch job etc etc, and we found a way... etc etc." People who know you and "Bob" will understand who really did the work.

That said, I would say my success at this sort of thing has been pretty low (although I am on a positive winning streak of one positive outcome in a row...)

    He’d accepted the impact on his personal life, after 
    many arguments about his work hours with his wife, etc…