Anderson Silva knocked Tito Ortiz out cold, but there's no bad blood between the MMA legends ... 'cause the day after, Spider gave his 1st class plane ticket to The Huntington Beach Bad Boys GF -- so she could sit with her man.
46-year-old Ortiz posted a video on social media thanking 46-year-old Silva for the sweet gesture.
"The biggest thing I think Anderson Silva has ever done to me, I'm very thankful. He just actually gave up his 1st class ticket for Amber to sit here," Ortiz says.
"The flight's messed up, the airline, Jet Blue, messed up.