Kizaru could do nothing but stall Luffy, but in the process of doing so he also got 1 shot. That's the facts here. In other words Kizaru only managed to do to Luffy what Yamato did to Kaido. Just replace Luffys return with Nika's time limit. That was Kizarus only win con. Make Luffy beat himself, as he was unable to beat him himself.
Even then Luffy had the energy to eat so fast he made after images, whilst Kizaru was paralysed, and at best managed to sit up. Luffy could've stretched his arms over, do a few more ACOC hits and it'd be lights out for Kizaru for the rest of the arc