What time of day. Or rather, does Goku have access to Oozaru? Just wondering, Goku wins either way most likely, I'm voting for him.
Sato has a significant AP advantage (don't know whether or not it's enough to one shot Goku but I doubt it).
But that AP advantage doesn't help much. Goku has a large skill advantage, which means a lot here. Sato's cognitive functions are reduced in Sugar Rush, so he isn't very intelligent, which only gives him a further disadvantage added on to his lack of actual combat skill and experience. Due to this, he's gonna have a very, very hard time landing a single hit on Goku, who's extremely agile (likely on par with a monkey) and has a small body, it's especially worse if Goku is aware of Sato's advantage in strength, which will make him prioritize defense. Goku also has a range advantage with the Kamehameha, which will do significant damage to Sato if it lands (Goku, especially at this point, doesn't use the technique lightly due to the large drain in stamina, he'd only use it if he was confident it would land). It's also worth noting that Goku has a large stamina advantage. So I imagine this'd just be Goku dodging Sato until Sato gets tired, and Goku finishes him off in his weakened and exhausted state. The only thing Sato could really hope for is grabbing Goku's tail. It's unlikely, especially because Sato probably wouldn't think of it in almost any scenario, but if he does, he wins.
If Goku turns Oozaru, it's blatantly a stomp. Goku at the start of the series is wall level, but jumps to building level between then and the 21st Tournament, meanwhile Oozaru is large building level even for start of series Goku. Give that addition to 21st Tournament Goku, and he one shots Sato, Goku's sheer size advantage, and the fact that Sato's puches wouldn't harm him in the least would just make it worse.