Guatemala City, Guatemala - 10 U.S. wrestlers remain undefeated at the Pan American Championships following preliminary action on Thursday. Sara Fulp-Allen (El Granada, Calif./Menlo College) won a gold medal at 48 kg/105.5 lbs.    Pool competition and medal matches will be completed on Friday.    In men's freestyle, Nick Simmons (Williamston, Mich./Michigan WC), Clint Musser (Akron, Ohio/New York AC), Kirk White (Tacoma, Wash./Dave Schultz WC) and Brian Keck (Cleveland, Ohio/New York AC) all won their initial pool matches.    Simmons, a 2003 NCAA All-American, pinned Luis Vasquez of Guatemala in his first match and defeated 2003 Pan American Championships bronze medalist Freddy Serrano of Colombia 12-9 in his second match at 55 kg/121 lbs.    Simmons will next face Ricardo Castillo of Ecuador in his final pool match. If Simmons wins, he will advance to the gold-medal match.    Musser downed his only opponent, Angel Castro of Colombia, 10-0 in his only pool match. If he defeats Marcelo Castro of Chile in his next match, Musser will advance to the gold-medal match.    White defeated his two opponents by a combined score of 17-0 at 74 kg/163 lbs. He will face Juan Chaparro of Mexico in his final pool match.    Keck won his first three matches in a five-man pool by a combined score of 12-2 at 120 kg/264.5 lbs. In his final match, Keck will face four-time World medalist and 2000 Olympic bronze medalist Alexis Rodriguez of Cuba. The winner will capture the gold medal.    2004 Big Ten champion Tom Clum (Arvada, Colo./Wisconsin WC) lost his first match in a five-man pool at 55 kg/121 lbs. 5-1 to 2002 World Champion Rene Montero of Cuba before battling back to win his next two matches.    Clum will next face Mauricio Gonzales of Guatemela. If Clum wins, he will capture the silver medal.    Also losing a close match to a top competitor was Tommy Rowlands (Columbus, Ohio/Dave Schultz WC) at 96 kg/211.5 lbs.    Rowlands lost 3-2 to four-time World medalist and 2000 Olympic silver medalist Yoel Romero of Cuba. Rowlands came back to win his next match, and is one win away from a silver medal.    In Greco-Roman competition, Russ Davie (Cleveland, Ohio/Cleveland State) won his first two pool matches at 120 kg/264.5 lbs.    Davie will face 2003 Pan American Games gold medalist Mijial Lopez of Cuba for the gold medal.    Also still in the running to earn medals in Greco-Roman are Jason Tolbert (Ft. Carson, Colo./U.S. Army) at 60 kg/132 lbs., Ron Muir (Colorado Springs, Colo./Unattached) at 66 kg/145.5 lbs., Steve Woods (Colorado Springs, Colo./U.S. Air Force) at 74 kg/163 lbs., Jeff Funicello (Gilbert, Ariz./Sunkist Kids) at 84 kg/185 lbs. and Brandon Ruiz (Colorado Springs, Colo./Elite WC) at 96 kg/211.5 lbs.    Ruiz finished his pool competition, a three-man weight class, 1-1, but based on his win by fall in the first match and 3-1 loss in the second match, he has an opportunity to capture a gold medal.    Muir, Woods and Funicello can all win silver medals with wins.    Undefeated U.S. women's wrestlers are Fulp-Allen at 48 kg/105.5 lbs., Danyelle Hedin (Kailua, Hawaii/Team Hawaii) at 55 kg/121 lbs., Alaina Berube (Escanaba, Mich./New York AC) at 59 kg/130 lbs., Stephanie Shaw (Waterford, Conn./Unattached) at 63 kg/138.75 lbs. and Stephany Lee (Honolulu, Hawaii/Missouri Valley) at 72 kg/158.5 lbs.    Fulp-Allen won both of her pool matches to win the gold medal. She won both of her matches by fall.    Hedin won her first two pool matches on Thursday. She will next face Dora Martinez of Guatemala. If Hedin wins, she will wrestle for the gold medal.    Berube is one win away from a gold medal after winning her first two pool matches at a four-person weight class. Berube defeated 2003 Pan American Championships gold medalist Joselin Rojas of Venezuela by fall in the first round.    She will next meet Pilar Parra of Colombia.    Shaw won her pool with two wins. In the gold-medal match, she will face either Juliana Borges of Brazil or Ana Gonzales of Venezuela.    Lee, a 2004 U.S. Nationals runner-up, defeated Rainiel Guerra of Venezuela by fall in her only pool match. She will next face Rosangela Conceicao of Brazil for the gold medal.