WATCH: Plenty of fight left in 37-year-old Nate Marquardt as he breaks out walk-off KO

Nate Marquardt was being written off more than three years ago.

The former Strikeforce welterweight champion lost four of his first five fights when he returned to the Octagon in 2013, with three coming within the distance, and his fans were crying out for the veteran to hang up his gloves before he suffered a serious injury. But he rallied against CB Dolloway late last year with a gorgeous knockout and refused to call it a day even after coming unstuck against Thiago Santos at UFC 198. On Saturday night, Marquardt proved that he's got plenty left to offer as he upset the odds and solved the tricky puzzle known as Tamdan McCrory on the Fight Pass prelims of UFC Portland. The 37-year-old dealt comfortably with the dangerous guard game of the much longer McCrory in the first round of their middleweight clash. But he didn't want to coast towards a decision, in spite of his superiority in the kickboxing department, as he robbed McCrory of his senses in the second round.

Nate Marquardt with the walk off knockout against Tamdan McCrory at #UFCPortland. pic.twitter.com/w19qAYjDza

— just mma™ (@justmma) October 2, 2016

A counter right hook wobbled McCrory's legs and as he struggled to shake off the damage, Marquardt perfectly timed a head kick that sent McCrory stumbling. Unwilling to inflict any gratuitous damage, Marquardt strolled confidently away from his rocked opponent and showed that there's an awful lot more fight left in the old dog yet. “A lot of the stuff we trained in the gym happened in the fight,” Marquardt said after the fight. “Tamdan was a lot better off his back. I knew he was going to be good off his back, but that guy is a stud there. I was in trouble a couple times there, but the experience paid off. "He wasn’t respecting my takedowns, so he just kept coming forward, and I knew I had to unleash the right hand. As soon as I saw he was hurt, I thought I would give him a couple fakes and he’d drop his hands.”