PHILADELPHIA — Fueled by an overwhelming partisan hometown crowd, Philadelphia welterweight Tahmir Smalls snared the biggest victory of his pro career, beating Jose Roman by 10-round unanimous decision Saturday night on the Jaron Ennis-Uisma Lima undercard at the Xfinity Mobile Arena.

The 26-year-old Smalls, from Ennis’ promotional stable, used a blistering right to the jaw in the third round to send Roman down for the second time in his career. Smalls (16-0, 11 KOs) then chased the wobbling the 31-year-old Roman the rest of the round, though he was not able to close.

The round did change the course of the fight decidedly in favor of Smalls, who won by scores of 98-91, 96-93 and 95-94. The defeat ended the winning streak of Roman (14-2, 6 KOs) at three.

After the knockdown, Smalls played the role of the stalker, sending Roman into retreat. The Puerto Rican was more interested in reaching the final bell than taking any chances and engaging Smalls.

In a six-round battle of undefeated 20-year-old super bantamweights, Mexican southpaw Sean Diaz held his own early on, showing a tricky style against the hometown favorite, Dennis Thompson, a lefty who opted to fight out of an orthodox stance.

Diaz was so filled with confidence, he began getting cocky in the second round against Thompson, making hand gestures and mocking both his opponent and the Philly crowd with his forearm across his forehead, while playfully aiming his right hand in the air.

Thompson, meanwhile, stayed in business mode. The fourth round was a back-and-forth affair, with neither fighter an inch from the other. That’s when Thompson began opening up, stepping back and pounding away at the shorter Diaz.

In the end, Thompson (8-0, 5 KOs) remained undefeated, while Diaz (9-1, 2 KOs) put in a solid, entertaining effort in the split-decision verdict.

In the first bout of the evening, B-side Naheem Parker pulled off a mild upset with a six-round unanimous decision at lightweight over previously undefeated Justin Palmieri. The 31-year-old Parker (6-3, 2 KOs) used a quick jab to get in and out, leaving the 25-year-old Maple Shade, New Jersey, fighter Palmieri (5-1, 3 KOs) swatting at air at times.

Lightweight Harley Mederos remained undefeated by stopping once-promising prospect Hylon Williams (16-7-1, 3 KOs) in the first round of a scheduled six-rounder. Mederos (9-0, 8 KOs) dropped Williams three times in the first, marking the sixth straight stoppage loss for the 35-year-old Williams. It was the seventh-straight stoppage victory for the 25-year-old Mederos.

Super featherweight Giorgio Visioli, a sharp-looking 22-year-old southpaw from the United Kingdom, beat 29-year-old James Wilkins (13-3, 6 KOs) by an eight-round unanimous decision. It marked the second-straight eight-round decision victory for Visioli (9-0, 6 KOs).

Super featherweight Zaquin Moses (5-0, 3 KOs), the 20-year-old southpaw cousin of Shakur Stevenson, made easy work of 28-year-old Antonio Dunton El Jr. (6-5-2, 2 KOs) with a sixth-round unanimous decision.