It depends on the pro.
Probably very rare for the pro to win 7-0. Too much random variation in unforced errors, once-in-a-while winners by the 4.5's, etc.
I think it would also depend on the 4.5's playing history. If they are older guys whose games have gone down over the years, they probably would do much better if they've seen (and hit) that kind of pace when younger than guys who got bumped up from 4.0 based on consistency and chasing down every ball.