Grandmaster Mark Paragua ended the four-game winning streak of compatriot GM Julio Catalino Sadorra Wednesday in the fifth round of the $100,000 Manny Pacquiao Cup Asian Continental Chess Championship at the Midas Hotel and Casino here.
Sadorra, playing black, defended with the French but blundered on the 31st move. He resigned two moves later.
Paragua said Barbosa placed his knight on the wrong square, allowing him to sacrifice a rook for inevitable mate.
"May malaking chance sa draw kung y'ung knight n'ya (Sadorra) ay nalagay sa c6 square para hindi ako makapag sacrifice," added the 29-year-old Paragua.
Paragua is alone on top with 4.5 points, half a point ahead of compatriots Sadorra, GMs John Paul Gomez and Richard Bitoon, GM Li Chao of China and top seed GM Le Quang Liem of Vietnam.
The nine-round Swiss System, organized by the GM Eugene Torre Chess Foundation, is sponsored by Rep. Manny Pacquiao, Cafe Puro, Alaxan, Oriental and Motolite Corp.
In other results, Gomez defeated GM Li Shilong of China after 33 moves of Gruenfeld defense; Bitoon edged GM Rogelio "Joey" Antonio Jr. after 47 moves of Catalan Opening; Li Chao routed GM Dao Thie Hai of Vietnam after 37 moves of Sicilian defense and Le split the point with GM Lalith Babu of India after 47 moves of Queen's Indian.
In the women's division, WGM Mary Ann Gomes of India outclassed WGM Guliskhan Nakhbayeva of Kazakhstan to create a four-way tie for first along with IM Batkhuyag Munguntuul of Mongolia, WGMs Guo Qi and Wang Jue of China with 4 points each.
The men's standings after 5 rounds (Philippines if not stated)
4.5 points - Paragua
4.0 - Sadorra, Le (Vietnam), Gomez, Bitoon, Li C. (China)
3.5 - Al-Sayed (Qatar), Adhiban (India), Lalith (India), Murshed (Bangladesh), Vidit (India), Gopal (India), Arun (India), Batchuluun (Mongolia), Nguyen (Vietnam), Dzhumaev (Uzbekistan), Sasikiran (India).