Chiongbian and Celdran combined for 156 points shooting rounds of 74 and 82 in the Modified Stableford Scoring System.
The remainder of the field of around 250 pairs will complete the tournament today hoping to give the upstarts a run for their money.
Chiongbian, who is married to the younger sister of his partner, carded rounds of 41 and 44 while Celdran shot 33 and 38 points.
At provisional second spot is the team of June Luna and Hospicio Razon with a total of 149 points on rounds of 72 and 77.
A point further back, are the teams of Macky Michael and Dino Yap (69-79) and Manuel Granada and Boboy Durano (71-77).
Three teams are tied with aggregates of 146 points. These are Bugs Unchuan and Jose 'Pito' Alvarez (71-75), Alvin Garcia and Tito Sotto (67-79), and Benjie Akol and Jun Basco (72-74).
Prizes at stake will be the overall championship for the team with the most points based on their net scores and the overall best gross.
Leading the pack in the race for best gross honors is the pair of former pro and many-time club champion Carl Almario and Jun Plana, a former national team member like his partner, with a two-day aggregate of 137 points.
Teams with a combined age of 120 years and up are also vying for honors in the seniors division.
Holding the provisional lead in that category is the team of Unchuan and Alvarez.
At second spot is the duo of Ricardo Go and George Go with 144 points.
Choy Sala, who heads the scoring committee, explained to The Freeman yesterday that a team can only win one prize. They will first chose the overall champion from all participants then pick the winner of the seniors' class from those who qualify based on the total age.
Then they pick the first runner-up for the overall and the seniors' until the last prize.
Those who will not win the overall awards can also qualify for best score for the round.
The major sponsors of the tournament are San Miguel Corp., UBS, Pilipinas Shell Petroleum Corp., Smart Communications Inc., and Cebu Mitsumi Inc.
Hole-in-one sponsors are Ford Cebu, Club Car/The Turf Company, Signal Trading Corp., Water Boss, and CICI Gen. Insurance.
Skygo is giving away a motorcycle for an eagle.
Also supporting the event are Darras + Bowler, Bank of Commerce, Chinatrust Bank, Northwest Hardwoods, Olio, Petron Corp./C.A. Gothong Lines, Profood International Corp., Prulife, San Sebastian/Alenter Foods, Sulpicio Lines, JY Square, Multi Turf Equipment Corp., Par Golf, and Cebu Progress Commercial.
The awards ceremony will be held tonight at the ballroom of Cebu Country Club.