Garlic Jr. easily, he beat both Goku and Piccolo. A kid version stand no chance
I'm to tired to watch those episodes on my PC but i remember Garlic in his normal form managed to fight Krillin who at the time (after Frieza) is well in the 10K+ PL. So Garlic in his normal form would easily win, nevermind his super form.
Fun Fact: Garlic Jr is immortal :)
First time we got too see Garlic he was owning 23 Budokai Goku and Piccolo at the same time. After that he comes back with the power of the Makyo Star and fights Frieza saga Piccolo and Krillin. Plus he has Immortality so Kid Goku gets Killed with one or two shots.