While focus will be on the Century Tuna full IRONMAN Philippines, a mix of fearless bidders from at least 29 countries mount their own drive for top honors in the Subic IRONMAN 70.3, which reels off Sunday in Subic Bay.

August Benedicto and Ines Santiago, who topped their respective sides in the 1.9-kilometer swim, 90km bike and 21km run event in Cebu last year, lead the chase for the overall Open championship and age-group honors in an explosive racing weekend at the country's premier triathlon hub.

It will be ushered in by the IRONKIDS on Saturday and highlighted by the third staging of the grueling 3.8km swim, 180km bike and 42km run race, also on Sunday.

But Benedicto and Santiago brace for a tougher challenge this time with a slew of aces all primed for a crack at glory, including 12 bidders each from Taiwan and the United States, 11 from Great Britain and eight and seven from Japan and Australia, respectively.

But the 301-triathlete strong local contingent is out to keep the title at home with John Alcala, who stole the thunder from the big guns to snatch the Puerto Princesa 70.3 trophy last November, leading the challenge, along with Jonathan Pagaura, Yoejan Prudente and Jocel Rendon.

Celma Hitalia, Mary Baluyot, Mae Cunanan, Vanessa Agdon, Eliza Fulgencio, Nerza del Rosario, Lourdes Ramos and Ma. Lourdes Cabero, on the other hand, seek to stop Santiago's domination of the distaff side.

Keen competition is also seen in various age-group categories, including the 18-24 division, 25-29, 30-34, 35-39, 40-44, 45-49, 50-54, 55-59, 60-64, 65-69, 70-74 and 75-and-above, both in the men's and women's classes.