By Lem Satterfield

Jaron Ennis transformed himself from prospect to a legitimate 147-pound contender.

The switch-hitting Ennis displayed speed, double-fisted power and killer instinct by scoring three knockdowns in the second round of his 12th straight knockout against veteran welterweight Raymond Serrano before his screaming, partisan, hometown Philadelphia fans on Friday night at the 2300 Arena in Philadelphia, ending a scheduled 10-round main event on ShoBox: The New Generation on Showtime.

In succession, the 21-year-old Ennis (22-0, 20 KOs) floored his man with a right hook out of the southpaw stance, right hand while orthodox, and, finally, with a hybrid-uppercut, right hand along the ropes.

The end came at 1:12 of the second round.

It was yet another impressive performance for the title-shot-seekingEnnnis, who out-landedSeranno, 13-0, in jabs, and 31-4 in power shots. Serrano (24-6, 10KOs) was stopped for the third time in his career, his previous losses were against fighters with a combined record of 89-1-1.

Ennis’ corner man is his father, Bozy, who also has trained older siblings, Derek Jr. and Farah. He continues to make noise in a deep and talent-filled division whose champions are southpaw Errol Spence (IBF), Keith Thurman (WBA), Shawn Porter (WBC) and switch-hitting Terence Crawford (WBO).

In the co-main event, “Tsumani” Samuel Teah (15-2-1, 7 KOs) hurt Kenneth Sims Jr. (13-2-1, 4 KOs) with left-right combinations in the second and fourth and nearly finished him at the bell ending the sixth of an eight-round unanimous decision.

A 31-year-old Liberian who was after his third straight KO, Teah had advantages in jabs (50-24) and power shots (170-112) and generally battered the 24-year-old Sims (13-2-1, 4 KOs) of Chicago in retreat.

In the opening bout, Ukrainian Arnold Khegai overcame a bleeding, third-round head-butt induced slit over his left eye and scored a sixth-round knockdown during an eight-round unanimous decision  over Jorge Diaz.

In his second fight on American soil in as many appearances at Philadelphia’s 2300 Arena,  the 26-year-old “Arni” Khegai (14-0-1, 9 KOs) hammered Diaz (19-6-1, 10 KOs) of New Brunswick, New Jersey on the ropes over the final 13 seconds but couldn’t register his second straight knockout.