Stalemate or possibly Kory. Fire is intangable in her green form, but lacks the power output to down Star. It's also possible Starfire could just absorb Fire and her blasts entirely since she's made out of pure energy.
Fire is not intangible.
She has been KOed many times due to physical contact.
And SF is on a whole different level in terms of strength, speed, durability, energy output and hth skills.
She has been KOed by energy shots that tore through her body in the OMAC Project Infinite Crisis miniseries (issue 4 I think)
Plus she is able to lift objects in that form thus proving she is not intangible.
These are just on the top of my head.
To lazy to look for more examples.