Defying the odds, the Purefoods TJ Giants whipped the San Miguel Beermen, 87-78, Sunday night at the Cuneta Astrodome to wrap up their semifinals series, 4-2, and head into a best-of-seven championship showdown against the top-seeded Alaska Aces in the 2009-2010 KFC PBA Philippine Cup. The Finals begin Wednesday. The Giants will be playing in the PBA all-Filipino Finals for the second time in three years and a record-setting 13th overall since they entered the league. It will also be the first title showdown between Purefoods and Alaska in 10 years. Purefoods has won four all-Filipino titles and will be gunning for a record fifth championship. Getting the Best Player of the Game award for the third straight time, Roger Yap stole the thunder from his more popular teammate and namesake James Yap as he scored 20 points, grabbed 11 rebounds and issued four assists to once again lead the Giants to victory. In the final minutes of the game, Yap hit two dagger-like baskets that punctured the heart of the struggling Beermen. James Yap added 18 points while Marc Pingris chipped in 15 points and 13 boards. It was Purefoods' third straight win against the powerhouse San Miguel squad after being down 1-2 in their semifinals series. As in their previous wins against their sister team, the Giants employed a crippling defense, dominated the boards and executed the right plays to stun the mighty Beermen who were the pre-tournament favorites on account of their beefed up roster with the acquisition of prized forward Arwind Santos and the return of Danny Seigle and Danny Ildefonso. But as in their two previous losses, the Beermen fell flat, unable to shake off the vaunted Purefoods' defense. San Miguel found itself relegated to a one-game battle for third place with sister team Barangay Ginebra also Wednesday. Santos led San Miguel with 20 points. The Giants built up a huge 20-point lead, 48-28, late in the second quarter. The Beermen came charging back in the third quarter to cut the deficit to a single-digit, 56-64. But the Giants whipped up another storm as the two Yaps joined forces once again to erect a 70-58 lead with 9:15 left in the game. San Miguel had a 7-2 run to come close again at 66-72 with 6:10 remaining. But Roger Yap scored twice on a buzzer-beating shot and then on an acrobatic drive to keep the Beermen at bay, 76