Outrage be damned ... the GGG vs. Canelo fight was a legitimate draw, says George Foreman -- who tells TMZ Sports the fighters should have been gunning for a knockout instead of a decision. 

Foreman says he watched the fight -- and thinks the judges collectively got it RIGHT scoring the match a draw because neither boxer fought well enough to walk away with the other man's titles. 

"The best way to win a boxing match is by knockout. The Triple G man couldn't pull it off and the other guy was scoring points on making him miss." 

Foreman continued, "You don't score points just by coming forward."

"In reality, they both came in as champions I would have allowed them both to leave as champions. I wouldn't have done any more than a draw."

Foreman says he does have a bit of advice for judge Adalaide Byrd -- who turned in a lopsided 118-110 victory for Canelo ... get your eyes checked!