NEW YORK – Midway through his fight with Joe Calzaghe last night, Roy Jones, Jr. became Roy Jones, Sr.

A boxing ring is a terrible place to age. It is as unforgiving to the aged boxer as klieg lights are to a faded film star. Saturday night a familiar landscape to Jones was transformed into a minefield by the speed of Calzaghe’s hands, the accuracy of his punches and the relentless passage of time.

Jones had no answers for any of them and because of it he took a fierce beating at Madison Square Garden, one that left his left eye lid split open and blood streaming into his eye and down the side of his face, giving him the appearance by the end of a bull in the ring, taunted, lanced and hopeless.

It became quickly evident that Jones had no legs left beneath him, no reflexes to free him and no chance to win. It was a sad state of affairs for a fighter who was once universally seen as the best pound-for-pound fighter in the world.

This is not to minimize Calzaghe’s work, which was impressive and patiently devastating. He pounded Jones’ body early in the fight, slit his left eye lid open wide and then alternated between taunting an opponent who had done the same so often to others and slapping him silly.

Things that had once been natural for Jones and had for so many years made him unbeatable deserted him, as they do all men in time and he was left a technically flawed stationary target for Joe Calzaghe to stab and punch at for 12 rounds on his way to a unanimous decision so lopsided he lost only the first round on the three judges’ cards.

Jones would have one brief moment then, when he sent Calzaghe tumbling awkwardly to the floor after a stinging right hand clipped him in the nose. Calzaghe tottered forward unsteadily as he rose, clearly stunned, but fought back well enough to keep Jones at bay. As things turned out,  that was the last time Jones was afloat all night.

By the end of the long night, the 39-year-old Jones had been bleeding steadily for five rounds, his hands now being used for as barricades against Calzaghe’s attacks than as weapons of mass destruction. It is difficult to score points when your gloves are being held high as if they were stapled to your ears, but such was where Jones too often found his.

“Those pitty pat punches were a little harder than I thought,’’ Jones (52-5, 38) joked after it was over but it was no joke. It was harsh reality and his bruised face showed it.

“I couldn’t figure him out. I couldn’t see out of my eye. He won the fight.’’

That was obvious from the second round on. After the first round knockdown, the only other time Jones landed a meaningful blow was when he caught Calzaghe with a right uppercut as the two leaned in at close quarters. That punch snapped the champion’s head back but did not sever him from his consciousness. And, it served no real purpose because Calzaghe (46-0, 32 KO) was by then peppering Jones with his straight right jab and quick flurries that were beating him to the face and rib cage and more and more often forcing him to keep his hands high to protect his chin.

“I was in my rhythm,’’ Calzaghe said. “I got great reflexes. Fighting with my hands down is my style and I know for a fact it’s very hard for anyone to fight my style.’’

Roy Jones could not, at least not this shadow purporting to be Roy Jones could not. This was the night all fighters ultimately face except for the rare few who leave before the sport rejects them. It was the night Jones became a senior citizen.

“I don’t know what I’ll do,’’ Jones said when asked about his future. “I’ll go home and talk to my team and my family. If I feel good I might fight again. If I don’t, I won’t.’’

He may feel good again in a week or two but he will never feel the same about himself as a boxer. There is no denying any longer what he is not.

When Antonio Tarver and Glen Johnson knocked him out in back-to-back fights and Tarver nearly did it a second time when they met again, Jones had an excuse, claiming he had tried to get back down to 175 pounds from the heavyweight limit too quickly and paid a price for it.

He took considerable time off and then had three comeback fights and won them all. This created what boxing is best at selling – a mirage.

Jones’ victory in January over a fat and ill-prepared Felix Trinidad was hailed as more than what it was – a seniors’ division match up in which the better prepared man prevailed. Instead it opened the door  to a shot at the RING magazine light heavyweight title held by the undefeated Calzaghe but it turned out not to be opportunity knocking. It turned out to be Joe Calzaghe knocking an old man around a boxing ring that grew ever smaller as the rounds wore on.

Calzaghe did concede “I was stunned’’ when Jones dropped him in the first round but he said he’d been down before, including in April when he defeated Bernard Hopkins after similarly going down in the opening round, and knew how to react.

When he got up, he fought back just enough to make Jones doubt that it was time to come in for the kill and so the former champion’s time passed before he realized it. After that, there was nothing left but to absorb a grim lesson on the aging process in boxing.

“I been down before and I got up (and won),’’ Calzaghe said. “That’s what champions are all about. When you put me down, I come back stronger.’’

When he managed to do that, Roy Jones had no answers. No counter moves. Nothing really but the ability to survive a mugging on 33rd and Broadway, one in which he escaped with his money but with no more illusions about what he has left.

“I don’t know what he’s going to do,’’ one of Jones’ associates said. “Where does he go from here?’’

If he’s smart, retirement.