Jesus Iribe flexed his left arm and raised it above his head, striking a triumphant pose amid a round of cheers ringside yesterday at Blasidell Center.

As photographers snapped away, Iribe, the underdog challenger to Brian Viloria's International Boxing Federation world light flyweight championship on today's 4:30 p.m. card, savored the moment.

It was, quite likely, Iribe's only chance to revel in applause and raise a victorious hand in Viloria's backyard and he was taking full advantage.

Of course, Iribe's "victory" yesterday could turn out to be Pyrrhic in nature. With Viloria looking on, it consisted of shedding a quarter pound — after a half-hour of sweating in the sun — at the afternoon weigh-in to finally make 108-pound limit and prompt a shout of "We have a fight!" from the announcer.

Now comes the hard part, dispatching the 25-2 (15 knockouts) Viloria in front of the home crowd. That's something that figures to require considerably more than a stroll around the block in a sweatsuit for Iribe (15-5-5, 9 KOs).

Viloria is a man on a mission, a champion once dethroned, not only aiming to hold onto this one before the home folks but set up a lucrative unification fight with longtime rival Ivan Calderon.

For Viloria, there is no margin for error here. No room for inexactitude or leaving anything to chance. Including his weight. Eight years in the pro fight game have taught Viloria well, sometimes the hard way, and it is reflected in the way he goes about his craft and his team attends to detail.

Viloria weighed in at 107 1/2 pounds and to see his expression upon climbing on the Hawai'i State Boxing Commission's scale was to know that there would be no surprises, that all contingencies had been accounted for and bases covered. "I've been right on target (for days)," Viloria said. "I've been able to eat. I've done my job."

Iribe, a counterpuncher in the first fight outside his native Mexico, said he thought he'd done his, too. His corner maintained their man had weighed spot on at another scale before heading to the weigh-in, where they were surprised by the discrepancy.

Iribe, who had been watching the weigh-in with studied nonchalance, his feet propped up on a chair seat to rest the legs, was forced to scramble. He had to suit up and sweat off the overage in the allotted two hours or risk, according to officials, losing a shot at the title and being slapped with a fine.

Ultimately, the actual shedding of the weight was, physically at least, mostly an exercise in inconvenience for Iribe. Mentally, it was a stress he clearly didn't need going into a fight where a lot needs to go right for him to win.