Chapter: 135, P6.1
Kame-sennin: “Despite the cute name, he was an outrageously fearsome person…His strength was extremely overwhelming…[ ] He was an opponent we were utterly unable to oppose; not only my younger self or Tsuru-sennin, but even our master, Mutaito. ”
Chapter: 142, P4.2
Context: Tenshinhan wants to fight Piccolo
Kame-sennin: “I understand how you feel, but his strength far surpasses the imagination. Even if we ganged up on him, we couldn’t possibly take him.”
Roshi wins this. He says ganging up wouldn't work, and prior says that his younger self couldn't do it. Young Roshi > 22nd Tenshinhan + 22nd Roshi