Stuart Scott -- Continued to Fight MMA ... With Chemo Port In His Chest

Stuart Scott was so passionate about continuing his MMA training during his fight with cancer, he REFUSED to quit ... even after doctors implanted a chemotherapy port into his chest.

"He was such an impressive person," says Sensei Darin Reisler ... who trained Scott in Connecticut.

"During his last round of chemotherapy, when he would train, he was training with the chemotherapy port surgically implanted in his chest. He did mixed martial arts... with a chemo port in his chest!"

Scott had said MMA training helped to get his energy up after grueling chemo sessions -- but Sensei Darin says Stuart wasn't just training to help himself.

"He really looked out for the needs of others. He was the first person to volunteer to work with a new student, and he always had a smile on his face."