I honestly think it could go either way. saitama has rapid growth, and could surpass goku fast if goku does goku things. but, if goku doesn't do goku things I think it would be an even fight, and come down to pure luck.
Saitama recently did punch a hole in a dimension/time/space in the Jump OPM. . .and before anyone says something about that not being canon or not the webtoon, just remember ONE writes both which makes both canon.
Saitama’s full powered serious punch just sent a shockwave that parted some clouds, Goku had to be careful while fighting cell as not to accidentally destroy the planet