[quote=@Weird Tales]
<Snipped quote by Double>

Having the stronger power level isn't an instant win. Frieza at full power was stronger than super saiyan Goku, but Goku kept on fighting and made him burn through his energy and beat him
[/quote]

What version of DBZ were you watching? Super Saiyan Goku was stronger right from the start, to the point where Goku was the one who stopped fighting because he was bored. There was even a filler scene of Frieza's men on another planet using a large scale Scouter that measured Frieza's power level just fine but broke down when it tried to measure Super Saiyan Goku. Goku was stronger at that time. Several times stronger in fact.