Two past Olympic medalists for the United States claimed victories in the first session of Greco-Roman wrestling at the Ano Liossia Olympic Hall in Athens, Greece, Tuesday August 24. The U.S. had four participants in the session.     Scoring two wins in the morning session was 2000 Olympic champion and 2001 World Champion Rulon Gardner (Cascade, Colo./Sunkist Kids) at 120 kg/264.5 lbs.    Adding a victory for the United States at 55 kg/121 lbs. was 1996 Olympic silver medalist Dennis Hall (Plover, Wis./Sunkist Kids).    Gardner was the first American to compete, and opened with a solid 3-0 victory over Minduagus Mitzgaitis of Lithuania.    After a first period passivity call against Mitzgaitis, Gardner scored a two-point gut wrench turn midway through the period and led 2-0 at the break. In the second period, with just over one minute left, Gardner worked behind Mitzgaitis and scored a takedown for this third point.    The U.S. suffered its first Greco-Roman loss, when  Oscar Wood  (Fountain, Colo./U.S. Army) dropped a 9-3 decision to Konstantinos Arkoudeas of Greece. Wood fell behind quickly, when Arkoudeas countered a throw attempt for two points early, the scored a gut wrench for a 4-0 lead. Wood trailed 7-0 at the break, but scored three quick points in the second period on a takedown and a front headlock turn. Arkoudeas added two takedowns to finish off the 9-3 win.    The next U.S. match came at 84 kg/185 lbs., where Brad Vering (Colorado Springs, Colo./New York AC) dropped a 4-0 decision to 2002 World bronze medalist Mohamed Mohamed of Egypt .    There were no points in the first period, so the second period started in the clinch. Mohamed locked first, and scored one point on a throw from the lock. At the 4:33 mark, after Vering was placed down with a passivity, Mohamed scored a three-point lift and throw on Vering for the final 4-0 margin.    The U.S. came back with a win at 55 kg/121 lbs., when 1995 World champion stopped Petr Svehla of Czech Republic, 3-2.     The match was scoreless in the opening period and went to the clinch. Hall locked first. After almost 40 seconds, Hall hit a sweet three-point headlock, with Svehla coming out from under with a one-point reversal, for a 3-1 Hall lead. Svehla added a one-point turn from the mat to close the score to 3-2, but could not score again on the highly-charged Hall.     Hall has won three career World-level medals, the 1995 World gold, a 1996 Olympic silver and a 1994 World bronze. He dropped in weight to make the Olympic team, his third Olympic berth (1992, 1996, 2004). Svehla was fourth in the 2003 World Championships.    Gardner had a tight match in his second bout, a 1-1 overtime referee's decision over 1996 Olympic bronze medalist Sergey Moreyko of Bulgaria. Moreyko is one of the veteran stars in the weight class and has won four World-level medals.    Both points were scored from the clinch position. After a scoreless first period, Gardner added the first point from the clinch to start the second period. Moreyko locked first and was required to score within one minute. After 60 seconds went by and neither athlete had scored or lost their lock, Gardner received one point. During the clinch to start overtime, Moreyko received one point when Gardner released his grip. No more points were scored, ending the bout at 1-1 after the full nine minutes.    Gardner received the victory by tie-breaking criterion because Moreyko was hit with two passivity calls, while Gardner received only one passivity.    In the final U.S. bout of the session, Wood was defeated by Jannis Zamanduridis of Germany, 5-2.    Zamanduridis scored two points in the opening period, but Wood came back to tie the match at 2-2 early in the second period with a front headlock turn. Wood attempted another front headlock shortly after, and Zamanduridis scored a two point reversal with exposure defending the move for a 4-2 lead. Zamanduridis added a late takedown for the final 5-2 margin.    The athletes are participating in the pool competition, which they must win in order to advance to the medal rounds. All four U.S. wrestlers will compete in the 5:30 p.m. session to complete their pool contest.    The other three weight classes in the Greco-Roman tournament weigh in this afternoon at 4:00 p.m.    U.S. match results from 9:30 a.m. session on Tuesday, August 24    55 kg/121 lbs.  Dennis Hall (USA) dec. Petr Svehla  (Czech Republic), 3-2    66 kg/145.5 lbs.  Konstantinos Arkoudeas (Greece) dec. Oscar Wood (USA), 9-3  Jannis Zamanduridis (Germany) dec. Oscar Wood (USA), 5-2    84 kg/185 lbs.  Mohamed Mohamed (Egypt) dec. Brad Vering (USA), 4-0    120 kg/264.5 lbs.  Rulon Gardner (USA) dec. Minduagus Mitzgaitis  (Lithuania), 3-0  Rulon Gardner (USA) won by ref. dec. over Sergey Moreyko (Bulgaria), 1-1, ot, 9:00    U.S. pairings for 5:30 p.m. session on Tuesday, August 24  55 kg/121 lbs.  Dennis Hall (USA) vs. Oleksiy Vakulenko (Ukraine)    66 kg/145.5 lbs.  Oscar Wood (USA) vs. Mkkhitar Manukyan (Kazakhstan)    84 kg/185 lbs.  Brad Vering (USA) vs. Mukhran Vakhtangadze (Georgia)    120 kg/264.5 lbs.  Rulon Gardner (USA) vs. Marek Mikulski (Poland)