Rene Santiago scored the victory of his career – winning the WBO light-flyweight title with a clear decision win over the defending champion Shokichi Iwata.

Santiago was a significant underdog in Tokyo, Japan and overcame some tough early rounds to deservedly win on the scorecards by margins of 118-110, 117-111 and 116-112. The Puerto Rican improves to 14-4 (9 KOs).

The challenger tried to get his jab going early on, and explored options with occasional right hands, but there was more intent in Iwata’s shots. The champion was on the front foot, and he applied more pressure in the second when targeting the body and trying to cut the ring off to get Santiago to engage.

Santiago had success in spots with his overhand right, but it was not enough of a deterrent.

A left hook downstairs from Iwata caused Santiago’s knees to dip in the third round, but Santiago kept jabbing and moving, and he landed a screw shot in his bid to keep Iwata off him. He also took another solid looking left hook that Iwata leapt in to deliver before the end of the round. There was a sense that the pressure was building on Santiago in the fourth and fifth as his output dwindled.

Yet he defiantly responded in the sixth, crashing in a good right hand after a flurry of blows in what was his best round since the first. Santiago was on his toes in the seventh and looked more comfortable as Iwata marched forwards, landing little. The champion lunged and missed on occasion in the eighth, prompting loud cheers from Santiago’s corner.

Iwata, who scored three stoppage wins in his three outings in 2024, was finding it tough to pin Santiago down – with the challenger landing some flashy shots in the ninth – although Iwata broke through late in the round and forced Santiago to endure a spell of pressure.

The 29 year old, from Tokyo, kept coming and worked the head and body, and although Santiago, 32, motored around the ring, he still fired out shots and there was swelling beneath both of the champion’s eyes.

Santiago’s corner told him that Iwata was tiring in the 11th, and the champion took a flush right hand near the end of the session.

It seemed everything could have been on the line going into the 12th. Santiago’s team felt that they were three minutes from victory and Iwata came out fast. But Santiago was aggressive in bursts, and Iwata looked one-dimensional and took more punches as he swung desperately to retain his title.

There was a tense moment when the disconsolate Iwata had his hand raised by the referee Ben Rodriguez as the decision was announced, but he had done little more than accidentally raise the wrong arm; Santiago and his team could celebrate.