I blame the anime for making people think Goku wasn't significantly ahead of Tenshinhan the entire fight prior to the use of Kikoho. The need to use Kikoho alone, in a tournament after Tenshinhan had arbitrarily decided that he no longer wanted to kill, should say enough, but luckily the fight itself clears any doubts. Tsuru made fucking Chaozu intervene lol. (I guess since the question is just which fight is the most one-sided, you could say the fight as a whole is less one-sided than I'm making it out by definition to be due to Chaozu's intervention itself...) Solar Flare is the single caveat and it's still a testament to Goku's speed that he avoided it, whether he was lucky that Roshi* had sunglasses or not.
Goku generally outsmarted Piccolo but this fight was far more challenging for him. Part of the added brutality comes from it being a true deathmatch, but still. Piccolo got one over him several times. Roshi beat Goku fair and square but the fight itself was not one-sided and Goku held the advantage many times, so I wouldn't necessarily say it's more one-sided than the Piccolo match or not. It's a tough call, they're pretty different fights, neither of which I feel like rereading to parse the exact degree of differences between fighters.
