Curtis Harper stuck around in the ring long enough to take out an unbeaten heavyweight.

A third-round knockdown and a late point deduction proved too much for Christian Thun to overcome, as Harper earned an eight-round, majority decision win. Scores of 78-72 and 76-73 in favor of Harper overruled an even 75-75 tally to produce the sizable upset in their eight-round heavyweight battle Saturday evening on ProBox TV from Whitesands Events Center in Plant City, Florida.

Harper has yet to live down the embarrassment of walking out of the ring once the bell sounded to begin his August 2018 bout with then-unbeaten heavyweight Efe Ajagba. Harper was dealt a disqualification loss, resulting in a suspension and which marked the start of a three-fight losing streak heading into this fight which he accepted on short notice.

Thun put his height and reach advantages to good use in round one. The 6’9 German heavyweight—now based out of Miami—worked his jab and long right hand against Harper, who fought behind a high guard while looking to sneak a counter shot. Thun wouldn’t allow it early but was cautioned by his corner to avoid getting caught up in a slugfest.

Harper—a Jacksonville native now based out of Clarksville, Tennessee—was able to close the gap in round two, landing an occasional body shot while also getting Thun to drop his hands low enough to score with right hands over the top. Thun took the shots well but found himself caught up in Harper’s style of fight, much to the dismay of his head trainer.

The fight took a drastic turn in round three.

Thun’s head snapped back from the impact of a right hand by Harper, who had so much more to give after that. An overhand right by the 34-year-old journeyman left Thun dazed as he fell to the canvas for the bout’s lone knockdown. Thun was able to beat the count and managed to buy a little more time when a subsequent exchange dislodged his mouthpiece. Thun was able to catch an additional breather when Harper lost his mouthpiece, though scrambling to immediately insert it as to not lose any momentum.

It didn’t work, as Harper took his foot off the gas in round four. Thun listened to his corner and kept it strictly boxing in his best effort to clear his head. Harper was largely inactive as he squandered the momentum shift, much to the disliking of head trainer Kelvin Garcia who got in his face in between rounds.

Harper heeded the advice, offering different angles for Thun in round five. The veteran heavyweight dropped his left foot back to get full leverage on his left hook. Thun was able to absorb the shots on the inside, wisely clinching whenever he was unable to respond.

Thun found himself on the inside for much of the sixth round. Harper was within his desired punching range to score with right hands down the middle and left hooks to the body. Thun was reduced to punch-and-hold, his only response to Harper’s increased aggression while also contending with a small cut over his eye.

The chance of an upset grew early in round seven. A point was deducted from Thun for excessive holding, though it appeared to awaken the unbeaten heavyweight. Harper did his best to make it a two-point round, doubling up on his jab and landing right hands upstairs. Thun connected with a left hook and then rocked Harper later in the round with an uppercut for the most competitive sequence of the fight.

Thun went back to basics in the eighth and final round. Harper walked forward and directly into a one-two from Thun. The combination didn’t discourage Harper, who plowed ahead and laid on Thun’s chest as he attempted to drive him to the ropes. Harper picked up the pace over the back half of the round, while Thun was forced to play defense at a time when he needed to let his hands go.

Thun falls to 8-1 (6KOs) after going the distance for just the second time in his young career.

Harper advances to 14-8 (9KOs) with the win, his first in nearly five years. It also marked his first victory over an opponent with a winning record since May 2014, which also came at the expense of an unbeaten heavyweight. Wedged in between were losses to former title challenger Chris Arreola, unbeaten contender Zhang Zhilei and losing every round in decision defeats to Mikheil Bakhtidze and Brandon Moore before putting it all together on Saturday for arguably the biggest win of his 12-year pro career.

Headlining the show, unbeaten junior welterweight prospect Cesar Francis (10-0, 6KOs) faces former WBO lightweight titlist Raymundo Beltran (37-9-1, 23KOs) in a scheduled ten-round contest.

Jake Donovan is a senior writer for Twitter: @JakeNDaBox