Moscow, Russia - Three U.S. Greco-Roman wrestlers remain undefeated following the first day of competition at the Ivan Poddoubny Tournament.    Completing day one competition with no losses for the United States were Kevin Bracken (Colorado Springs, Colo./New York AC) at 66 kg/145.5 lbs., Darryl Christian (Colorado Springs, Colo./New York AC) at 74 kg/163 lbs. and Dremiel Byers (Colorado Springs, Colo./U.S. Army) at 120 kg/264.5 lbs.    Bracken, a four-time U.S. World Team member, posted wins over Vyatsheslav Masloboev of Latvia, 3-2, and Sergei Krasilnikov of Ukraine, 4-3.    Christian defeated Oleg Sobchuk of Ukraine by technical superiority, 13-3, in his only match of the day.    Byers, returning to Moscow where he captured his World title in 2002, dropped Sharudi Aubov of Russia, 3-0, in his only pool match of the day.    Competition at the Ivan Poddoubny Tournament will resume on Sunday morning. Continue to check TheMat.com for updates.    Ivan Poddoubny Tournament  at Moscow, Russia  Jan. 31-Feb. 1, 2004  U.S. Results  55 kg/121 lbs. - Lindsey Durlacher, Colorado Springs, Colo. (New York AC)  LOSS Victor Korlabev (Russia), 5-1, ot    60 kg/132 lbs. - Glenn Nieradka, Colorado Springs, Colo. (U.S. Army)  LOSS Sergei Belobaba (Ukraine), 3-1    60 kg/132 lbs. - Joe Warren, Colorado Springs, Colo. (New York AC)  LOSS Akop Mazan (Russia), 3-0    66 kg/145.5 lbs. - Kevin Bracken, Colorado Springs, Colo. (New York AC)  WIN Vyatsheslav Masloboev (Latvia), 3-2  WIN Sergei Krasilnikov (Ukraine), 4-3    66 kg/145.5 lbs. - Marcel Cooper, Stafford, Va. (U.S. Marine Corps)  LOSS Intagon Javodov (Russia), 4-0  LOSS Ambako Vachadze (Russia), 3-0    74 kg/163 lbs. - Darryl Christian, Colorado Springs, Colo. (New York AC)  WIN Oleg Sobchuk (Ukraine), 13-3    84 kg/185 lbs. - Jake Clark, Colorado Springs, Colo. (U.S. Marine Corps)  LOSS Demitre Kruglik (Belarus), 6-3    84 kg/185 lbs. - Brad Vering, Colorado Springs, Colo. (New York AC)  LOSS Denis Forov (Russia), 4-2    96 kg/211.5 lbs. - Dan Hicks, Quantico, Va. (U.S. Marine Corps)  LOSS Michael Bakelev (Russia), 5-2    96 kg/211.5 lbs. - Justin Ruiz, W. Salt Lake City, Utah (New York AC)  LOSS Sergei Lishtvon (Russia), pin, 1:43    120 kg/264.5 lbs. - Dremiel Byers, Colorado Springs, Colo. (U.S. Army)  WIN Sharudi Aubov (Russia), 3-0