Forty-year-old Nonito Donaire is the betting favorite when he battles Mexican Alejandro Gonzalez in his bid to become a world champion again on 29 July in Las Vegas.

Latest figures from the United States list Donaire at -190 ($190 wins $100) and Santiago at +160 ($100 wins $160) in their duel for the vacant World Boxing Council bantamweight throne at the T-Mobile Arena.

The betting line still favored Donaire simply because of his wealth of experience, tremendous skill set and immense power.

Even at 40 years old — and coming off a brutal knockout loss to Naoya Inoue more than a year ago — Donaire remains a livewire foe in the eyes of oddsmakers.

Santiago, younger by more than 13 years, is a tricky and durable opponent who has what it takes to frustrate Donaire.

But, according to experts, if Donaire catches him with his lethal left hook early, the Mexican's going down hard.

Santiago, however, is no pushover.

He battled Jerwin Ancajas to a controversial draw in 2018 and has vastly improved since then, making him a tough nut to crack for a guy who is in the twilight of a Hall of Fame career.

The Donaire-Santiago showdown will take place underneath the Errol Spence vs Terence Crawford world welterweight clash.

Originally scheduled for 15 July at the Cosmopolitan in Las Vegas, the Donaire-Santiago match looms as a treat for fight fans.

A four-division world champion, Donaire is regarded as the most accomplished Filipino fighter in history next to Manny Pacquiao.

Donaire answers the bell with a 42-7-0 record with 28 knockouts while Santiago totes a 27-3-5 mark with 14 knockouts.