By Peter Lim

In a stunning upset, Dat Nguyen (20-3, 7 KOs) scored a jaw-dropping sixth-round TKO over previously undefeated Miguel Flores (21-1, 9 KOs) in Flores' hometown of Houston. Nguyen took the fight on four-weeks' notice and weighed in 1.25 pounds over the contracted 128-pound weight limit, which he attributed to a faulty scale.

Nguyen, 35, had fought just two six-round bouts last year after a three-year layoff while Flores, 24, had a breakout year in 2016, winning three fights culminating in a career-best performance against fellow-prospect Ryan Kielzcweski.

The fight, aired on Fox Sports 1, was co-promoted by Savarese Boxing and King Promotions.

In the early goings, it appeared that Flores' youth and speed would prevail as he beat Nguyen to the draw with his longer reach and superior speed. He stung Nguyen with stiff jabs and one-twos from the outside and when Nguyen closed the distance, Flores confidently stood his ground with snappy hooks and uppercuts to the head and body he fired in fluid combinations. But while Flores' crisper shots bounced harmlessly off the older, rustier fighter, Nguyen's punches seemed to rattle Flores each time he landed even grazing shots.

The writing was on the wall.

In the sixth round, Nguyen trapped Flores against the ropes and hurled a murderous left hook-overhand right salvo that dumped Flores to the canvass. Flores beat the count on spaghetti legs and Nguyen relentlessly unleashed a two-fisted assault that prompted the referee to spare Flores from further punishment at the 1:02 mark.

Nguyen said his biggest victory to date was due in large part to maturity and patience. Previously trained by Buddy McGirt, Nguyen said he was, for the most part, self-trained for this fight, pulling together an impromptu and mish-mash patchwork of sparring partners who doubled up as punch pad holders in his training camp

"In the past I'd try to knock them out in two or three rounds and that was my downfall," Nguyen said. "I wasn't looking for the knockout. It just came. My key to victory was to fight the fight that I wanted to fight to dominate him. At first I was going in there to box him but he was actually a pretty good boxer who had long reach and good speed, but I saw that I had more success on the inside. He got tired and eventually I closed the gap and got lucky and caught him with a good punch. I knew God was watching over me for this fight."

"He was a great warrior, all Mexican fighters are, but I trained hard and came out on top tonight," Nguyen added. "He's a good fighter and he will be a champion one day so he just needs to keep his head up. Winning and losing is part of the fight game."

Equally gracious in defeat, Flores said, "I got a little too comfortable in there and he made me pay for it. In this sport you can't let your guard down. Anything can happen with an eight-ounce pair of gloves. We just got caught off guard an that's what you saw tonight. Things didn't go my way tonight. Hats off to Dat Nguyen. He's a hell of a fighter and he was a lot stronger than I thought. He got a big win tonight, he's back in the mix and I'm not the type of fighter to make excuses. Kudos to him and his team and I wish him the best"