Games Sunday (The Arena, San Juan) 2 p.m. - National University vs Perpetual (playoff for QF) 4 p.m. - San Sebastian vs Adamson (start of QF) National University and University of Perpetual Help System Dalta clash in a playoff for the last quarterfinal berth this Sunday even as San Sebastian-Excelroof kicks off its semis drive against a resurgent Adamson side in the Shakey's V-League Season 7 second conference at The Arena in San Juan. The Lady Bulldogs swept the Altas, 25-14, 25-20, 25-22, in their elimination duel but the former have dropped their last five games, enabling Perpetual to get a crack at the last quarterfinal berth with a crucial 3-1 victory over ousted St. Benilde last August 8. Gametime is at 2 p.m. with NU expected to pin its hopes again on top hitter Mervic Mangui, Maricar Nepomuceno, Elain Sagun, Jocelyn Soliven and guest players Denise Santiago and Daphne Santiago. Perpetual, on the other hand, hopes to get back at NU behind Nica Guliman, Ronerry dela Cruz, April Sartin, Michelle Datuin, Norie Diaz and Mary de Luna and get into the mix of fancied teams in the league sponsored by Shakey's Pizza. Also out for revenge are the Lady Stags, who are raring to get even with the Lady Falcons, who stopped the former's four-game run via a thrilling five-setter last July 29. But San Sebastian, which never dropped a set in its first four matches, bounced back with another pair of straight-set victories over NU and Far Eastern University to clinch the top spot after the elims with a 6-2 slate. Ateneo missed joining SSC at the helm as it bowed to Adamson, 1-3, settling for joint runner-up with its tormentor at 5-2 going into the single round quarters phase. Meanwhile, the NU-Perpetual Help game will be shown on NBN-4 starting at 2 p.m. tomorrow while the SSC-Adamson clash will be telecast on Tuesday.