No, Goku in his Super Saiyan forms could not beat Baby Vegeta in their initial encounters.
Here's a breakdown of why:
Goku vs. Baby Vegeta: Initial Confrontations
The question is generally about the early fights between Goku and Baby. Here's what we know based on the reference:
- Goku's Base and Super Saiyan Forms: When Baby was possessing Vegeta, Goku's child form could not win, even while using Super Saiyan forms.
- Super Saiyan 3's Shortcomings: During their first major fight, Goku transformed into a Super Saiyan 3 but couldn't maintain the form for long, indicating that Baby Vegeta's power was greater than a SS3.
Why Baby Vegeta was Stronger
- Baby, even in his Vegeta-possessed form, was too strong for Goku's Super Saiyan forms at the time.
- The reference notes that SS3 was not enough to defeat Baby Vegeta, which shows he was more powerful at that point.
- Baby Vegeta was able to quickly recover from a lot of SSJ3 Goku’s attacks.
The Turnaround
- It is important to note the exception in this question: Super Saiyan 4 Goku. In his adult body, Goku, when transformed into Super Saiyan 4, was able to defeat Baby Vegeta.
Conclusion
In their early confrontations, Goku's Super Saiyan, Super Saiyan 2, and even Super Saiyan 3 forms were not enough to defeat Baby Vegeta. Baby was simply too strong in his early encounters with Goku. The turning point comes when Goku transforms into a Super Saiyan 4 as an adult.