UFC fighter Rachael Ostovich's MMA fighting husband has been arrested for ATTEMPTED MURDER days after allegedly breaking his wife's face ... and he's still behind bars in a Honolulu jail.
TMZ Sports broke the story ... Ostovich -- who had to pull out of her scheduled January fight with Paige VanZant -- was hospitalized this weekend with serious injuries -- including a broken orbital bone -- after her husband allegedly assaulted her during an argument at their home.
Cops in Honolulu opened a domestic violence investigation earlier this week .