Casas continued to sizzle in his bid for a second straight crown, firing a six-under par 66 while Pucay sustained his form to shoot a 67 after a 66 as they shared the lead at 11-under 205 heading into the final 18 holes of this P700,000 event.
Ranged against Pucay and Elmer Salvador, Delariarte, who showed up the revered men of the tour in the first two days with rounds of 65 and 69, flinched and fumbled with a 74, the only over-par round submitted by the top nine players in a day of low scoring at the bunker-laden layout. He blew his four-shot lead and fell three strokes off the joint leaders at 208.
That enabled the lesserlight Salvador to gain a share of third place as the 1999 Epson Classic winner shot his third straight under par round -- a 70 -- even as two-time Asian PGA Tour leg champion Rodrigo Cuello and veteran campaigner Dan Cruz fired identical 69s to be at 209.
But for many, the chase for the top P100,000 purse of this event sponsored by College Assurance Plan, Manila Southwoods Manor, Smart-zed, Ericsson Telecommunications, Wilson, Publicis Spark and Callaway as among the donors, is reduced to a two-man affair.
Benjie Magada had a 71 while Vic Santia rallied with a 67 but the two remained too far behind at 210.
"Eto na yung palo na hinahanap ko," said Casas, whose five-stroke victory in the recent Philippine Open at Wack Wack signalled the return to form of the countrys top shotmaker next to Frankie Miñoza after going winless for 18 months.
He couldve smashed the course record 64 set by Swede Daniel Olsson in the 1996 World Amateurs but Casas flubbed at least four birdie putts inside four feet, including on the final two holes.
But Casas indeed is on a roll as his 66, a 32-34 card marred by a missed-green bogey on the par 3 12th, sustained his eerie run of under par rounds, including four in the RP Open.
Pucay, once regarded as the next Miñoza but whose rise to fame has been slowed down by poor form until he switched coaches from George Walker to the ever-reliable Roger Retuerto, couldve also seized a one-stroke lead but for a costly miscue on the par 5 17th. After barely reaching the green in two, Pucay chipped poorly and three-putted from 25 feet for bogey.
"Sayang din yun. But Im still comfortable with my position and I hope to finally win this one," said Pucay, winner of five pro events but whose victory came way back in 1999 in a rain-shortened Philip Morris Classic at the Orchard.
Putting did Delariarte in as the 22-year-old amateur flubbed makeable birdie chances although it was his double-bogey mishap on the par 4 18th, where he dumped his approach shot into the bunker and blasted poorly, that ruined his 35-39 round.
"I was frustrated with my putting," said Delariarte, who nevertheless led the amateur division by four strokes over RP Open low amateur tormentor Angelo Que, who had a 68 and a 212.
But Pucay said Delariarte cracked up as the pressure mounted at the backside as the erstwhile two-day leader missed back-to-back two par putts from No. 11 inside four feet and completely lost his bearing and rhythm with that closing 6.