NEW YORK – Jahi Tucker overwhelmed D’Andre Smith to remain unbeaten Saturday night on the Artur Beterbiev-Joe Smith Jr. undercard.

Tucker battered Smith for most of the final three rounds of their welterweight bout at Madison Square Garden’s Hulu Theater. A New York State Athletic Commission physician eventually instructed referee Shawn Clark to stop the one-sided action at 2:27 of the fourth round.

Smith (11-2, 5 KOs), of Decatur, Georgia, never went down, but he took an inordinate number of punches from the 19-year-old Tucker (8-0, 5 KOs).

Tucker, of Deer Park, New York, first hurt Smith in the second round, when he unloaded countless unanswered power punches on the defenseless Smith.

In the previous bout, Floyd Diaz honored the memory of his grandfather Saturday night by defeating Daniil Platonovschi.

Diaz, whose paternal grandfather died Saturday afternoon, recorded a six-round, unanimous-decision victory over Platonovschi to remain unbeaten. Judges Ron McNair and Robin Taylor scored all six rounds for Las Vegas’ Diaz (5-0, 1 KO), who won their junior featherweight fight 59-55 according to judge Eric Wolinski.

Moldova’s Platonovschi lost for the first time as a pro (4-1, 2 KOs).

Diaz remained in control throughout the sixth round, when it become obvious Platonovschi needed a knockout to win.

Diaz connected with back-to-back right hands with just over a minute remaining in the fifth round. A left hand by Platonovschi got Diaz’s attention about 1:10 into the fifth round.

Diaz landed multiple straight right hands during the fourth round.

A straight left hand by Platonovschi backed up Diaz just after the halfway point of the third round. An entanglement sent Diaz and Platonovschi crashing to the canvas about 50 seconds into the third round.

A right hook by Platonovschi knocked Diaz off balance with about 30 seconds to go in the first round.

In the bout before Diaz’s victory, middleweight prospect Troy Isley stopped Donte Stubbs in the sixth and final round of their fight.

Isley (6-0, 4 KOs), of Alexandria, Virginia, dropped Stubbs twice, once apiece in the fourth and sixth rounds, before referee Charlie Fitch stopped the action 38 seconds into the sixth round.

An overhand right by Isley sent Stubbs to the canvas, face first, just 29 seconds into the sixth round. Stubbs (6-6, 2 KOs, 1 NC) beat Fitch’s count, but he was not in condition to continue.

Isley first floored Stubbs with a right hand that left him flat on his back with 10 seconds to go in the fourth round.

Stubbs, of Riverside, California, has lost six straight bouts, but he hadn’t been knocked out before Saturday night.

Keith Idec is a senior writer/columnist for He can be reached on Twitter @Idecboxing.