Mizugaki came up short in his US debut, but he presented himself at the end of the main event fight as Torres' toughest challenge to date.
"You're a great challenger," Torres told Mizugaki after the fight. "I didn't expect that great of a fight out of you. I have a lot of respect for you. No one has ever taken me that far."
Torres scored more on strikes to win the decision on the scorecards unanimously and retain his bantamweight belt for the third time.
The WEC awarded Torres and Mizugaki each a $10,000 bonus for the Fight of the Night.
In the other post-fight awards, Anthony Njokuani earned bonus for Knockout of the Night and Rani Yahya won the Submission of the Night.