SINACABAN, Misamis Occidental — As her more illustrious Filipino compatriots fell on the wayside,  Woman International Master (WIM) Marie Antoinette San Diego was on fire on a humid Thursday, posting back-to-back wins against foreign rivals to seize the women's open solo leadership before the 7th Asean Individual Chess Championships took a break here Friday. After an impressive victory over Woman Grandmaster (WGM) Altan-Ulzii Enkhtuul of Mongolia, San Diego played with more confidence in handling the white pieces on Thursday afternoon's fifth round, besting erstwhile unbeaten and frontrunner WIM Bordoloi Pratitee of India  in 41 moves of the Queen's Gambit Declined. So dominant was San Diego's execution in taking the opening advantage that it led to a favorable tactical melee, thus paving the way for Pratitee to lose a rook, then her queen. The 27-year-old San Diego from Dasmariñas City now has 4.5 points as she handles black at the top board opposite Indian WIM Shakira Devi Herfesa, who has 4.0 points, when the games resume on Saturday here at the Asenso Misamis Occidental Resort and Adventure Park (Amorap). "Talagang magaling si San Diego medyo out of form lang  'nung ginawang elimination that she missed the cut for the Philippine women's team in the recent Samarkand Olympiad. Mas disiplinado siya ngayon (San Diego is truly talented. She just happened to be a bit out of form during the elimination that is why she didn't make the cut for the Philippine women's team for the recent Samarkand Olympiad. She is more disciplined now)," San Diego's former chess coach with De La Salle University Susan Grace Neri-Gonzales told The Manila Times. While the Asean chess fest offers a direct WGM title for the champion in the women's open field, Neri-Gonzales said San Diego's toppling of the top guns at the half of the nine-round Swiss System event had already gained her a WGM norm with performance ratings of 2488. Playing on board 3, Mindanao's biggest female hope WIM Ruelle Canino from Cagayan de Oro took a breather when she gained the upperhand in the opening phase of a Sicilian defense tiff against Herfesa. The country's youngest Olympiad campaigner heads to the middle game with a pawn up and a dominant center. But choosing to complicate matters rather than exchanging major pieces dearly cost her the match. "Nag-panic ako," said Canino, who was time-pressured and outdueled by Herfesa in the race for queening passed pawns. Canino's mentor and Olympiad teammate in the country's only WGM Janelle Mae Frayna won her fifth-round assignment, but early losses dropped her to 19th spot in the 34-man field with only 2.5 points to show heading to the last four rounds. Foreign visitors have continued to dominate the men's rivalry with eight of them making the top ten in the leaderboard headed by the unbeaten duo of International Master (IM) Erdene Baasansuren of Mongolia and Grandmaster Duck Hoa Nguyen of Vietnam with identical 4-point output. Just in striking distance is the highest performing Filipino, FIDE Master Alekhine Nouri from Escalante, Negros Oriental at third place with 3.5 points. While compatriot GM Darwin Laylo, who is also undefeated but with many draws, sits at 7th place with 3 points. "Pero malayo pa 'yan, marami pa ang pwedeng mangyari (It's too early to tell, many things can still happen)," Laylo said. Mindanao hopeful IM Christian Gian Carlo Arca of Zamboanga, after suffering his second loss, rebounded with a victory over veteran Cebuano IM Rico Mascariñas to join a big bunch of 2 pointers in the top 20 among 40 competitors in the men’s side.