Justin Quiban let slip what could have been one of his strongest starts in an International Series event, bogeying the final two holes to card a two-under 69, dropping to a tie for 47th with 17 others, including compatriot Miguel Tabuena, in the first round of the PIF Saudi International at Riyadh Golf Club, Saudi Arabia on Wednesday.

Chang Wei-lun showcased near-flawless precision with his iron game and putting, shooting a 64 to share the lead with Sadom Kaewkanjana. The two held a one-stroke edge over Yubin Jang and Joaquin Niemann, setting up what promises to be an intense four-day battle in the season-ending $5 million championship of the Asian Tour and International Series.

Kaewkanjana delivered a superb eight-birdie round, one better than Chang’s seven. However, a three-putt bogey on the par-3 17th allowed the Taiwanese ace to catch him atop the leaderboard.

Quiban displayed brilliance on the back nine, recovering from a mixed one-over front nine with an eagle on the par-5 12th, followed by consecutive birdies from the 15th. But the Filipino struggled under pressure, failing to save par on the final two holes, finishing with a 35-34.

Despite this, Quiban impressed from tee to green, hitting 16 of 18 fairways and finding 14 greens in regulation. His putting, however, was less consistent, with 31 putts across the round.

Tabuena, fresh off a career-best third-place finish in an International Series in Doha last week, started strong with back-to-back birdies from No. 3. But the ICTSI-backed shotmaker faced a challenging stretch, scrambling for pars on six of the next 11 holes.

A birdie on 16 brought him to three-under, but like Quiban, he stumbled with a three-putt mishap on 17 to finish with a 33-36.

The two Filipinos remain in a competitive group alongside big names like Louis Oosthuizen, Bubba Watson, Martin Kaymer, Tyrrell Hatton, Harold Varner III and Ryan Moore.

Both aim to step up in the second round to bolster their respective bids for spots in the final 36 holes.