The judges scored the bout 98-92, 97-93 and 97-93.

The win was Sylve’s third in a row since his lone defeat, a sixth-round knockout against Lucas Bahdi in 2024.

Sylve (14-1, 10 KOs) was sharp in the first half of the fight. His speed and movement allowed him to outbox Diaz, 33. He consistently landed his right hand to the head and body, which gave him an early lead.

Diaz’s moments were too few and far between, as he struggled to cut off the ring. And even when he closed the gap most of the fight, Sylve was able to clinch to thwart his attack.

The southpaw was at his best in the late rounds, when he finally worked his way inside and landed big left hands. However, his 22-year-old opponent survived to earn the most significant win of his career.

Diaz (34-10-1, 15 KOs), a former IBF 130-pound champion, has now lost three in a row and nine of his last 11.

The tough stretch includes losses to three-division champion and current WBO welterweight titleholder Devin Haney, two-time junior welterweight world champion Regis Prograis, William Zepeda and Oscar Duarte.