Mendes scored the victory 30 seconds into the third round. Not only was it the first TKO of Guida, it was Mendes' fourth consecutive KO win since dropping a bout to featherweight champion Jose Aldo Jr. last year.
Over the first two rounds, the Guida of recent vintage emerged -- the one who moves and moves and moves, but doesn't do a hell of a lot else. Mendes stuffed Guida's takedown attempts and effortlessly scored his own.
Early in the third, Mendes caught Guida flush on the jaw with a right hand, which sent Guida rocking backwards. Mendes pounced when Guida hit the mat and unleashed a series of right hands until Yves Lavigne stopped the bouts.
"That was a goal coming into the fight," Mendes said of becoming the first fighter to KO Guida. "That's what I wanted to do. I needed to make a big statement I want Jose Aldo, I want that belt."
Mendes improved to 15-1; Guida is now 31-14 with three losses in past three fights.