I posted a pic a few pages back showing Flash saying he is faster than heat vision. Which he is by the way but when he was outrunning the heat vision Superman was right behind him.
I know Flash is faster than Superman but I dont think the difference is gonna help Flash very much. But then again he can always steal Supermans speed. But on the other hand Superman has his durability, strength, and various vision and hearing powers also that he could use if Flash takes away his speed.
In AOS #642 Superman took out Martian Manhunter, John Stewart, Hawkman, Black Canary, and Flash.
He even made the comment something like "Wally is fast enough to see it coming but not fast enough to do anythig about it."
Flash can win but he must utilize his slight speed advantage wisely.