Perfect punch or long layoff.

Both contributed to the likely end of Brian Minto’s professional boxing career.

Minto, 37, seemed in control of his NABF heavyweight title eliminator against Tony Grano two weeks ago. He easily won the first two rounds and opened the third round by continuing to establish his left jab.

That’s when Grano landed the punch of the fight, a solid right that sailed just over Minto’s jab and landed squarely on the Butler fighter’s chin.

Minto got up at the count of seven and valiantly flailed away at Grano. In doing so, however, he left himself open, was floored again and the fight was over.

Just like that.

While Grano’s punch was perfect, it’s natural to wonder if ring rust didn’t contribute to Minto’s defeat.

That fight was Minto’s first bout since October of 2010 — and he didn’t get much of a workout that night as outclassed foe Pierre Karam retired after two rounds.

Minto went 15 months between fights. And we’re talking about a guy who fought twice in 2010, three times each in 2009, 2008 and 2007.

His best in-ring performances came when he was a busy fighter. Never afraid to be a brawler in the ring, Minto brought the rare combination of defense with him to each fight.

He was knocked down twice by Chris Arreola and three times by Marco Huck. But Arreola had three inches and 40 pounds on him and Huck was the unbeaten WBO cruiserweight champion.

The guess here is that if Minto fights Grano a few months earlier, the outcome may have been different.

It’s not that the guy wasn’t in shape. He always trained hard, entering the fight at a comfortable weight with his body looking as toned as ever.

A boxer can train and spar repeatedly, but there is no substitute for true competition.

This is not to suggest the long layoff was Minto’s fault or that of his handlers. Prospective fights fell through during that 15-month period and Minto’s career had reached a point where taking on a club fighter locally would have been a waste of time.

Kittanning’s Belmont Arena may host a fight card in April and Minto is considering being part of that card in what could be his farewell fight.

Or he may simply decide to retire now.

This is a guy who didn’t turn pro until two months before his 28th birthday. He wound up defeating Vinny Maddalone in a brutal fight that won ESPN’s Fight of the Year Award. He derailed legendary German heavyweight Axel Schulz’s comeback attempt, packed Pullman Park for two fights and took on Huck for the world cruiserweight championship.

That’s not a bad body of work.

If this is the end of Brian Minto’s boxing career, it is one worth celebrating.

Just the same ... You’d love to see him get another shot at Grano.