After a sizzling 67 Monday, Pagunsan started practically on the wrong foot this time, stumbling with a double-bogey on the opening hole and failing to recover those strokes with a two-over par for the day.
Artjanawat followed up his first-round one-under par 71 with a two-under 70 to catch up with Pagunsan at 141 while Indonesias Indra Hermawan also gained ground on the Filipino ace shotmaker with an even 72 for a two-day haul of 143 at second place.
While the Thai and the Indon bets are now breathing down Pagunsans neck, the other Filipino players remained too far behind the leaders with John Bayron and Joselito Zaragoza tied with Bruneis Hj Hamidon Damit at 20th, 13 strokes off the pace, and Marvin Dumandan at 24th, three more shots behind.
Bayron matched par 72 while Zaragoza and Dumandan had identical 76s.
At the start of the ladies individual play, Carmellete Villaroman carded a three-over 75 to be in third place in a tie with Thai Morakod Kladpetch and trailing the two other Thai entries. Villaromans teammates Heidi Chua and Ruby Chico-Walker submitted a 78 and an 80, respectively.
Titiya Plucksataporn and Onnarin Sattayabanphot made it 1-2 for the Thais after the first of three rounds of play in the ladies competition with a 71 and a 73.
It was a terrible day for Pagunsan as he didnt only start badly but also finish poorly.
He went even following birdies on Nos. 6 and 12 only to yield strokes again on the last two holes after missing the green on both for a bogey-bogey finish.
Pagunsan also struggled on the green, missing at least five birdie-putts from within five feet.
"Masama na ang umpisa, hindi pa ako maka-putt," rued the Negrense shotmaker.