yes. third fret b string is like the "rock G". Important is to mute the high e-string here since that note is not part of Gmaj!
the fingering x-2-0-0-3-x means B-D-G-d which is a proper Gmaj, but since the B is in the bass it's called G/B.
If you like you could still play x-2-0-0-3-3 which is even more like the "rock" version, just has an additional high g but it's still G/B