The 40-year-old Cuello took the cudgels for a three-man Filipino squad ranged against the worlds top players as he gunned down four birdies in a 34-36 round marred by two bogeys as he found himself joining the big group at 17th place in this prestigious event staking $1.3 million to the winner.
Smith upstaged the big guns, including world No. 1 Tiger Woods, as he led the siege of the Australians at the 6,989-yard layout with a sizzling seven-under par 65 for a one-shot lead over compatriot Paul Gow, who like Smith, took advantage of a windless morning flight to shoot a 66.
Three other Aussie bets turned in a 67, while Woods overcame the afternoon winds to fire a 68.
But while Cuello, who won the Omega PGA Championship in Hong Kong in 1997, seemed to be enjoying top form, having come from two impressive finishes in the Asian PGA Tour in the last two weeks, the two other Filipinos struggled in the face of world-class opposition.
Danny Zarate could only shoot a 74 in a 38-36 card marred by four bogeys as he shared 88th place with six others, nine strokes off the pace.
The big letdown, however, was Cassius Casas who dropped seven strokes right in the first four holes at the back where he teed off as the rigors of his gruelling stint in the US PGA Tour qualifier finally taking their toll on the fancied Filipino shotmaker.
Although he birdied Nos. 14 and 16, Casas holed out with a bogey on No. 18 then fumbled with three more mishaps in a birdie-less stint at the front. He wound up with an 81 (39-42) and was last in a field of 132.
Hundreds of fans thronged the course, queuing up from early morning in the largest spectator presence at a golf tournament in Thailand. Smith, a late riser, said after his round that even his wife was surprised that he had been up at 5 a.m. for the early tee off.
"My goal was to hit a lot of pars at the start of the round and take the stress away from needing to get up and down from the rough," Smith said.
He missed the fairway on No. 7, chipped it back, hit a six-iron to the left fringe and chipped in from five yards. That, he claimed, was his most difficult hole.