Shane Mosley boxes well for a 44 year old with the wear and tear of close to 450 rounds under his belt but the 23-year veteran is shell of the elite boxer that won major world titles at lightweight, welterweight and junior middleweight in the late 1990s and 2000s.

The proof? Mosley lost to David Avanesyan on Saturday at the Gila River Arena in Glendale, Arizona. Avanesyan (22-1-1, 11 knockouts), who won a 12-round unanimous decision against the future hall of famer, is a solid fighter, a 27-year-old welterweight fringe contender, but he wouldn’t have been fit to spar with Mosley 10-to-15 years ago.

That version of Mosley (49-10-1, 41 KOs), however, is long gone and nothing — not even enlisting the services of the great Roberto Duran to train him — was going to bring him back. Mosley, who ended a brief retirement last year with stoppage victories over Ricardo Mayorga and Patrick Lopez, still has some spring in his legs but his reflexes and the pop in his punches have faded over the years.

The Southern Californian was able to out-jab a tense Avanesyan in the opening round of the CBS Sports Net-televised fight, but the Russia-born Armenian gradually fought through his nerves in Rounds 2 and 3, and was imposing measured aggression on the older man by Round 4, stalking behind a high guard and landing hard-and-sneaky right hands. By Round 5, Mosley’s jab was non-existent. The man who was once an offensive machine (anyone remember his “power boxing” years at lightweight?) struggled to let go with power punches and was reduced to looking for pot shots while bounding around the younger man.

The lowest point for Mosley came when he was docked a point for a low blow by referee Wes Melton in Round 10. The point deduction lit a fire in Mosley’s belly and the old lion took it to Avanesyan in the final minute of the round and continued to be the aggressor in the final six minutes of the fight (especially Round 12, when he finally connected with head-jarring right crosses).

However, the rally came too late. Judge Raul Caiz Sr. had the fight way too close with his 114-113 tally but judges Sergio Caiz and Dennis O’Connell scored it 117-111 (which was in line with the way most observers on Twitter saw it).

In the co-featured bout, Mosley’s son Shane Mosley Jr. pulled out a six-round majority decision against Roberto Yong, a 32-year-old journeyman from nearby Phoenix who had been inactive for three years. Mosley (7-1, 5 KOs), a 6-foot-1 super middleweight, has now won five in a row since suffering a split-decision loss in a four rounder in 2014, but his latest victory did not come easy.

Yong (5-8-2, 4 KOs) gave him problems with his awkwardly athletic and mobile southpaw style. Mosley, 25, was stung a few times in Rounds 3, 4 and 5, but like his old man, he rallied in the final round, rocking Yong with a big right hand. This time the customary Mosley surge was enough to get the edge on the scorecards, which read 59-55, 58-56 and 57-57.