Superman dominates every fight, but the phoenix's immortality makes permanent victory impossible.
Superman can destroy the phoenix with heat vision, freeze breath, or physical force. But it comes back. Every time.
The phoenix's divine fire might actually hurt Superman (divine = magical), making this more interesting than the power gap suggests. But Superman's speed and strength let him control every engagement.
This is another 'wins the battle but not the war' scenario. Superman can never permanently defeat the phoenix, but the phoenix can never defeat Superman.
The phoenix is immortal โ every death is a rebirth. Divine fire is magical and could bypass Kryptonian defenses. Healing tears provide self-sustaining combat ability.
Superman's speed lets him destroy the phoenix before it can attack. Heat vision, freeze breath, and physical force are all effective. Superman can simply contain the ashes to prevent rebirth.
Superman 'wins' every fight but can't permanently stop the phoenix. His ability to contain or scatter the ashes might prevent rebirth, giving him the overall edge.
Phoenix also fights
Superman also fights