Mark Lisi and Carey Talley scored a goal each as D.C. United claimed a 2-1 victory over Arnett Gardens at RFK Stadium and win their CONCACAF Giants Cup quarterfinal series, 5-1, on aggregate goals. United advances to the semifinals of the competition, where it will play the winner of the series between Comunicaciones of Guatemala and Mexican power Guadalajara on Aug. 3 at a venue to be determined. The final of the Giants Cup is slated for August 5. Mike Ammann had an impressive debut for United in goal, saving Fabian Davis’ penalty kick in the 14th minute with a deflection to his right. April 11 in Washington, D.C. D.C. United (USA) 2 Arnett Gardens (Jamaica) 1. Goals: Talley (pen.) 30, Lisi (Quaranta, Namoff) 86; Earl (Wilson) 23. DC United — Ammann. J.Cooks, Watson, Talley, Denton (Goodlett, 80), Lisi, Alegria, Kamler (Nelsen, 46), Convey (Namoff 62), Quaranta, Thompson Conteh. Arnett Gardens — Collins, Barnes, Stevens, Eldemire, Chin-Sue; Richards (Richardson, 84), Neil, Davis (McLeod, 90), Shedden, Wilson, Earl. Att.: 9,117