SALVADOR, BRAZIL - Top-seeded Lisa Arce and Holly McPeak of the Women's Professional Volleyball Association have advanced to the semi-finals of this weekend's FIVB Beach Volleyball World Championship Tour event after winning two of three matches here Friday.

A pair of Manhattan Beach, Calif., residents, Arce and McPeak defeated WPVA rivals Karrie Poppinga and Angela Rock 15-7 before dropping a 17-15 decision to third-seeded Shelda Bede and Adriana Behar of Brazil.

Arce and McPeak, winners of seven WPVA and two FIVB events this season, advanced to the semi-finals by eliminating sixth-seeded Liz Masakayan and Elaine Youngs of the WPVA 15-2. Masakayan and Youngs had beaten Arce and McPeak 15-13 in their last meeting September 28 at Lihue, Kaua'i, Hi.

With the win, Arce and McPeak face second-seeded Monica Rodrigues and Adriana Samuel of Brazil in Saturday's second match with the winners of the match between Bede and Behar versus third-seeded Sandra Pires and Jackie Silva.

Masakayan and Youngs, who won two WPVA titles in 1997, dropped a 15-10 match to Pires and Silva, the 1996 Atlanta Olympic Game gold medalists. Masakayn and Youngs eliminated 16th-seeded Sarah Straton and Christine Wilson of Australia 15-2 and fifth-seeded Barbra Fontana and Nancy Reno of the WPVA 15-11 before losing to Arce and McPeak.

Fontana and Reno, who finished fourth in an international event at Marseille, France in June in their first-ever pro event together, started Friday by eliminating 13th-seeded Angela Clarke and Natalie Cook of Australia 15-11 and seventh-seeded Maike Friedrichsen and Danja Musch of Germany 15-12 before being eliminated by Masakayan and Youngs.

Seeded ninth, Poppinga and Rock finished ninth in the international event after being eliminated 16-14 by Gerusa Ferreira and Rejane Secches of Brazil. Poppinga and Rock placed second in the 1997 WPVA finale in Hawaii by dropping the title match to Masakayan and Youngs 15-13.

Desiree Leipham and Deb Richardson, the fifth WPVA team in the competition, finished 13th. Seeded 23rd, Leipham and Richardson were eliminated by dropping a 15-8 match to 15th-seeded Danielle Gattelli and Lucilla Perrotta of Italy. Here are the WPVA results (seed):

Thursday - Championship bracket, first-round - Arce/McPeak (1) def. Chiaradia/Fontana, SUI, 15-1; Poppinga/Rock (9) def. Folco/Nascimento, ITA (24), 15-7; Fontana/Reno (5) def. Nessa/Risia, BRA, 15-13 (28); Masakayan/Youngs (6); def. Storch/Gougeon, CAN (27), 15-3; Leipham/Richardson (23) def. Adriana Bento/Ana Richa, BRA (10), 16-14. Championship bracket, first-round - Arce/McPeak def. Straton/Wilson, AUS (16), 15-6; Poppinga/Rock def. Jorgensen-Sommer, DEN (25), 15-11; Bruschini/Solazzi, ITA (12) def. Fontana/Reno, 15-4; Masakayan/Youngs def. Maria/Sarmento, POR (22), 15-5; Friedrichsen/Musch, GER (7) def. Leipham/Richardson, 15-7. Contender's bracket, second-round - Leipham/Richardson def. Folco/Nascimento, ITA (24), 15-13; Fontana/Reno def. Schoon Kadijk/R. Kadijk, NED (11), 15-10. Friday - Championship bracket, quarter-finals - Arce/McPeak def. Poppinga/Rock, 15-7; Pires/Silva, BRA (3) def. Masakayan/Youngs, 15-10. Championship bracket, semi- finals - Shelda Bede/Adriana Behar, BRA (4) def. Arce/McPeak, 17- 15. Contender's bracket, third-round - Gattelli/Perrotta, ITA (15) def. Leipham/Richardson, 15-8; Fontana/Reno def. Clarke/Cook, AUS (13), 15-11. Contender's bracket, fourth-round - Ferreira/Secches, BRA (14) def. Poppinga/Rock, 16-14; Fontana/Reno def. Friedrichsen/Musch, GER (7), 15-12; Masakayan/Youngs def. Straton/Wilson, AUS (16), 15-2. Contender's bracket, quarter- finals - Masakayan/Youngs def. Fontana/Reno, 15-11. Contender's bracket, semi-finals - Arce/McPeak def. Masakayan/Youngs, 15-2.