By Keith Idec

NEW YORK – It wasn’t easy, but Amanda Serrano made history Saturday night.

Serrano fended off a tough challenge from Argentina’s Yamila Esther Reynoso to win a 10-round unanimous decision and capture the vacant WBO super lightweight title on the Danny Garcia-Shawn Porter undercard at Barclays Center in Brooklyn. The strong southpaw won by the same score, 99-91, on the cards of judges Larry Hazzard Jr., Joseph Pasquale and Waleska Roldan.

The 29-year-old Serrano (35-1-1, 26 KOs), a native Puerto Rican who resides in Brooklyn, became the first women’s boxer to win world titles in six weight classes. The 22-year-old Reynoso (11-5-3, 8 KOs) has lost each of her three world title fights.

Serrano previously captured championships at bantamweight (118 pounds), super bantamweight (122), featherweight (126), super featherweight (130) and lightweight (135). She took an unusually difficult route toward winning those titles because she went down to featherweight, then super bantamweight and then bantamweight – 17 pounds lower than lightweight limit of 135 – after winning the WBO lightweight title in August 2014.

Reynoso tried throughout the 10th round to score the knockout she knew she needed to upset Serrano. She couldn’t hurt Serrano, though, and took some hard punches from the champion in those three minutes.

By the ninth round, Reynoso was bleeding badly from her nose. For the second time in three rounds, Reynoso hit Serrano with a right hand following the bell to end the ninth round.

Serrano and Reynoso traded power shots as part of an exciting exchange near the center of the ring when there was just under a minute remaining in the eighth round.

Reynoso backed Serrano into her own corner late in the seventh round and landed a couple flush right hands. Reynoso also hit Serrano with a right hand after the bell sounded to end the seventh round.

Serrano hurt Reynoso in the first round, but Reynoso withstood that trouble and eventually landed shots that affected Serrano. By the third round, they had reversed roles, with Reynoso backing up Serrano, who was the aggressor earlier in their bout.

Serrano hurt Reynoso with a left to the body with just over 30 seconds to go in the first round. Reynoso retreated, but quickly fired back a right hand at Serrano to briefly keep Serrano from attacking her.

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