I think Izuna wins in the long run.
Sasuke will most likely give Izuna a lot of trouble, mainly from his Sharingan and Genjutsu. Since Izuna resists both his fire and electricity jutsus, he'll have to go for those to beat her. Izuna resists mind/fear manipulation & paralysis, but not illusions or pain/perception manip, so I think she would still get trapped in the genjutsu (?). Add in the fact Sasuke can predict Izuna's taijutsu and weapon mastery, and can see her even if she's invisible, and she'll have trouble.
However, Izuna holds powerful hax, which I think will win her the fight. The Bishamon Boots and Seikan Talisman both revive Izuna after death or KO, Yami-Uchi sends someone to the void, Fuuma seals him into the talisman, Kou'un turns him into a random object, Metsubou is an OHKO, she has access to massive amounts of healing & status effects (including blindness), can match Sasuke's flight and Enhanced Vision with Winged Boots/Light Pill & Awakening Pill respectively, she can teleport, Sword Defender and Weapon Breaker make his sword attacks barely effective, and Martial Boots block his ranged attacks. Sasuke's Sharingan can copy her taijutsu and energy attacks, but not her Talismans or weapon effects, meaning not only Sasuke won't know what effect is coming for him (among the 30+ different effects), but he won't be able to copy them either.
Even if Sasuke traps Izuna in genjutsu, since it's in his personality and fight methodology to kill rather than torture, he'll kill her on the spot. She'll come back to life, realize she got trapped because of Sasuke's eyes, blind him with Mikiri or Darkness Pill (or immobilize/paralyse/put him to sleep with Ashikase/Jinrai/Suimin), and then proceed to hax him with one of the aforementioned talismans.