Which Danny Phantom fan hasn't thought of this?
The way I see it, the fight breaks out right there in the lab. Danny is knocked out, and the Fenton devices around the lab won't do any good. As a last resort, Jazz jumps in the ghost portal and zaps herself.
W00t! Go Jazz!
And yes, I realize there's no emblem on her chest. Danny didn't hop out of the portal with it so really, Jazz shouldn't either. As for her having powers Danny didn't have initially... I dunno, Jazz is smarter. XD