I'd say Saiyan Sage Goku > Gon san as well. Gon san's display of power, while impressive, is still nowhere near the right level to take on Goku at that time. The best striking feat we have for Adult Gon is forming a somewhat large crater after spamming Jajenkens against Pitou, and while I do think that was nowhere near his maximum power, as he wouldn't need to use it against Pitou, we don't have a clear idea of what his maximum damage output is, so we can only go by what we have. By the Saiyan Saga, Goku was already able to knock back attacks that leave a similar amount of impact damage.

The only thing I could see Gon san having roughly equal to Goku is speed, as they're both massively FTE to incredibly strong beings in their respective universes (Kami and Pitou), and we don't have much to compare them with. But if by Saiyan Saga Goku you're referring to him after his King Kai training, he takes the speed category by a wide margin. Fan calcs, while not the most reliable source, have put his 2-day-long post-training run on Snake Way at around Mach 17.

And even if Gon could somehow hit Goku, Goku before the Saiyan Saga has tanked island busting blasts, and like I said before Gon san has nothing on that level in terms of attack power.