Following ten tough rounds' action, the three judges had the talented teenager a wide winner against Perez (9-10-1, 1 KO).

97-93 and two 98-92 scorecards was the final verdict as Zamorano (15-0, 1 KO) reeled off a third championship defense, nearly a year after being elevated to full champion following RING and undisputed titleholder Tina Rupprecht's retirement from the sport aged 33.

If she has improved over the last six months, Saturday wasn't a glowing assessment against lowly opposition.

While the youngster began promisingly, Zamorano cuffed shots and missed plenty of her attempts as time wore on, failing to utilise her physical gifts to their maximum potential.

That allowed Perez to walk her down, make it an increasingly taxing encounter and one where her reactive defense was exploited. Jabs continued to connect cleanly through her guard, while Perez's pressure continued as the Mexican roughed her up at close quarters.

Although she did enough to win, this represented a routine - and anticlimactic - title defense against an opponent no-one expected to give her so much trouble. She'll need to be sharper with her fundamentals against better quality foes in future.