Del Rosario, winner of the 26th Malaysian Open, breezed through Round Two with 188 pinfalls to beat Chinese Taipeis Pan Yu Fens 159 points while second seeded Shalin Zulkifli (242 pinfalls) outclassed Sarah Yap (202).
Yap qualified for the semifinals when she beat lone Indonesian bowler, Sheanny Gunawan, 214-148. Facing Shalin in tomorrows women semifinals is another Malaysian, Wendy Chai, who booked her semis berth by defeating her sister, Sharon Chai, 215-188, in the earlier round.
In the mens division, top seed Azidi Ameran (199) of Malaysia downed Yousif Falah (183) from Bahrain. Azidi will face Rivera in the mens semi-finals match.
Rivera, who won a vintage car for his perfect game in the Malaysia International Open, amassed 220 pinfalls to qualify over Qatarian Abdulla Al Qatan, who had 177.
Valdez, the No. 2 seed, will meet Duane Camacho from Guam in the second set of the semifinals round after beating Yannaphon Larpapharat of Thailand, 204 191. Camacho easily trounced Singapores Alvin Kwang, 211- 158.
The event is supported by Royal Selangor and organized by ESPN STAR Sports. Sunway Lagoon Resort is the official hotel for the Malaysian leg.