I think Itachi takes this but saying Itachi will win because "He would have died against Sasuke so Itachi should beat him" is wrong.
Sasuke most succesful attack was chidori which clearly did little to the raikage. Everything else was the Raikage's doing. During 80% of the fight Sasuke was put on the defensive using the shield of black flames, something that Itachi hasnt shown able to do.
There is still speculation that genjutsu might not work on Raikage whilst he is in Raiton shroud and I am sure Guillotine Drop would have ended Sasuke if Gaara never came.
Anyway I say Itachi wins this, cant be bothered to explain how though.