Clavecilla, who started the day tied with Gaston at the helm, reeled behind the former national amateur champion with a bogey-marred 38 at the frontside in another punishing day at the ravine-laced layout.
But the Luisita bet never got discouraged and fought back with a brilliant 34 to regain the lead heading into the final round of this event presented by Harbour Centre and backed by Mizuno, Nestea and Summit mineral water. He had a 150.
Gaston, playing out of Negros Occidental Golf and Country Club, took the solo lead with a 37 at the turn but failed to match Clavecilla’s fiery windup and slid to second place with 151.
With the rest of their pursuers, including defending champion Rolly Viray, dropping farther behind with awful rounds, the battle for top honors is reduced to the two members of the RP squad which won the Asia-Pacific Men’s Seniors golf crown in China last year.
"It’s gonna be a good fight tomorrow (today). But I can’t just let Francis take control because if he does, it would be difficult for me to catch up," said Clavecilla in Filipino.
Seve Chua Roxas carded a 77 and stood in third place with a 160, 10 strokes adrift, while three strokes farther back is Joe Lao, who had a 163 after an 83.
Bryan Cockrell shot a 77 to tie Edwin Arcilla, limping with an 80, at 165 while NGAP vice president Danny Pizarro groped for form with an 85 to share seventh place with Caloy Coscoluella, shooting an 81, at 167.
Jose Nepomuceno had an 84 for a 169 while Viray, winner of the event at Mt.Malarayat last year, bowed out of contention with an 86 and a 170, 20 strokes behind Clavecilla.
Lao, just two shots behind Clavecilla and Gaston after the first 18 holes, fumbled with 41-42 while Pizarro, four behind the erstwhile joint leaders at the start of the round, had too many bogeys for a 45 and hardly recovered with a 40 going home.
Chua, five behind before the second round, moved to within four with a 36 at the turn, but lost his touch, rhythm and all at the back and wound up with a 41 and a 77.