In the Freeza Saga, Gohan, Krillin, Piccolo, and Vegeta all battle Freeza from his first form to his final. At each stage, someone is able to over power him, if even slightly and cause him damage, thus sapping portions of his energy reserve. Likewise, Freeza's transformations require energy for him to transform to the next level, thus using more energy.
Lets assume that Freeza never made the unnecessary transformations, never fought the others, Goku could already transform into a Super Saiyan, and both fighters had their exact same power levels and fighting abilities.
Freeza had been fighting the others for at least half an hour longer before Goku even showed up and Goku was at full strength when their battle first began. Freeza was also using less than a quarter of his own power while fighting Goku in his base form, 50% while Goku was a Super Saiyan, and 100% by the end, at which point he was actually equal, if not stronger than Goku. If I remember correctly, the only reason 100% Freeza didn't dominate Goku is because he was tired from the extended fighting he had done.
So, if these two warriors had met from the start and done so at full power, with Goku having the ability to transform, and Freeza not making any useless transformations, would Goku have won their battle?
FYI: It's not opinion based because I'm asking about both characters at a specific time when all information required to determine and answer is provided canonically. This isn't like a "Who's faster Superman or Flash?" question. Both characters strengths and weaknesses are clearly defined and at no point vary. If you don't know, don't mark for closure, that's not grounds to close a question.