GLASGOW – UFC welterweight Gunnar Nelson said the punch that put him ahead early against Santiago Ponzinibbio came with an eye-poke that left him seeing double.

“I’m kicking myself in the head for not stopping the fight,” Nelson (16-3-1 MMA, 7-3 UFC) told MMAjunkie following his first-round knockout loss to Ponzinibbio (25-3 MMA, 7-2 UFC) in the FS1-televised headliner of UFC Fight Night 113, which took place at SSE Hydro in Glasgow, Scotland. “I should have stopped the fight, recovered, and carried on from there.”

Nelson landed an uppercut and a left hook early in the fight. But he caught a straight right hand that sent him reeling and set up a fight-ending flurry of punches. Ponzinibbio picked up a TKO at the 1:22 mark of the opening frame in an upset.

Nelson said he kept fighting because he believed he had Ponzinibbio on the ropes.

“Because I caught him, I thought I had him on the run and I could finish the fight,” Nelson said. “I think that was the biggest mistake in this fight.

“I’m not saying that if I didn’t get caught by it that I would have seen the shot coming. It is what it is. Even then, I was seeing double, and I was able to land a few more shots. But then he catches me with a nice right hand.”

In fact, Nelson would not have the ability to stop the fight if the alleged foul was not caught by the referee. But in practice, many referees stop the action if a fighter complains about an illegal move.

Ponzinibbio said he had no recollection of an accidental eye-poke during the fight and pointed to the finishing sequence that put away Nelson.

Nelson, a submission grappling ace, said the lesson moving forward is obvious.

“Obviously, I have to be more careful,” he said. “I got caught with a punch that I should have seen coming. I don’t like to make excuses, but this is the truth, how I feel, anyway. I should have stopped the fight when I got poked. I was seeing two Ponzinibbios in front of me, and it was like that until I remember standing up and the fight was over.”

Now, he can only hope the loss doesn’t set him too far back on the UFC’s welterweight ladder.

For complete coverage of UFC Fight Night 113, check out the UFC Events section of the site.