Sort of. They tie a couple of times. The first time is their first meeting, in which the battle ends before it can be resolved, although Goku later reveals that he could have defeated Buu then if he had not wished to give his sons a chance to defend the planet on their own. As it stands, the only major characters past or present to actually defeat Goku in battle are Jackie Chun (Master Roshi), Tienshenhan, King Piccolo, Raditz, Captain Ginyu (temporarily, as the battle was postponed), Perfect Cell, and Baby.