All four U.S. wrestlers won their matches in the morning session, claiming their pool competition and qualifying for the quarterfinal round at the Olympic freestyle wrestling competition at the Sydney Exhibition Centre on September 30.     Claiming victories were Terry Brands (Lincoln, Neb./Hawkeye WC) at 127.75 pounds, Lincoln McIlravy (Iowa City, Iowa/Hawkeye WC) at 69 kg/152 lbs., Charles Burton (Bloomington, Ind./New York AC) at 167.5 pounds and Kerry McCoy (Bethlehem, Pa./New York AC) at 130 kg/286 pounds.    The United States has now put together three straight sessions of unbeaten wrestling, winning 12 matches in those three sessions. The U.S. has a 17-3 record in the freestyle tournament to date, including a loss in a re-wrestled match that had been won.    Brands was dominant on his feet, taking down Chvista Polychronidis of Greece repeatedly in an 8-1 win. The only point Brands allowed was on a questionable escape early in the bout. Brands will compete against David Pogosian of Georgia in the quarterfinals.    McIlravy scored a hard fought but impressive win over Yuksel Sanli of Turkey, the 1999 World bronze medalist. Sanli scored the only point of the first period on a caution and one point penalty against McIlravy for fleeing the mat at 2:38. In the second, a flurry of action was scored two points for each wrestler at the 3:50 mark, making it 3-2 for Sanli. From that point on, McIlravy opened up his takedown attack, scoring four consecutive points on takedowns at 4:10, 4:53 and 5:35 for the 6-3 win. McIlravy will face Ivan Diaconu of Moldova in the quarterfinals.    Burton just scored a strong 10-0 technical fall over Gregory-Herve Martinetti of Switzerland. He led 3-0 in the first period on three leg attacks, then opened it up in the second with a pair of three point takedowns to the back and another straight single leg. Burton wins his pool and makes the quarterfinals. Burton will battle  Magomed Ibragimov of Macedonia on Sunday morning.    McCoy opened up the offense from his feet and on the mat for a 10-0 technical fall at 4:52 over Rajab Ashabaliyev of Azerbaijan. He opened with a three-point throw, then a one-point leg lace for a 4-0 lead in the opening 1:20. He added another takedown and a two-point leg lace for a 7-0 lead at break. His points in the second period were a caution and one for fleeing the mat against the Azerbaijani. He closed it out with an ankle lace for two points. McCoy will face Artur Taymazov of Uzbekistan in the quarterfinals.    THE TIME FOR THE SUNDAY MORNING SESSION IS 9:00 AM, a change from the time sessions on the other seven days of the wrestling competition. THE TIME OF SUNDAY'S EVENING SESSION IS 2:30 P.M., a change from the time sessions of the other seven days of wrestling competition.    Two other U.S. wrestlers will compete this evening in gold medal finals, starting at 5:00 p.m.: At 54 kg, Sammie Henson (Norman, Okla./Sunkist Kids) is in the gold-medal finals against Namik Abdullayev of Azerbaijan. At 76 kg, Brandon Slay (Amarillo, Texas/Dave Schultz WC) will battle Alexander Leipold of Germany, a 1994 World champion and multiple World medalist.    Freestyle Wrestling, September 30, 9:30 a.m. session    54 kg - Sammie Henson, Norman, Okla. (Sunkist Kids)    No match this session - will compete in gold-medal finals    58 kg - Terry Brands, Lincoln, Neb. (Hawkeye WC)    dec. Chvista Polychronidis (Greece), 8-1    69 kg - Lincoln McIlravy, Iowa City, Iowa (Gateway WC)    dec. Yuksel Sanli (Turkey), 6-3    76 kg - Brandon Slay, Amarillo, Texas (Dave Schultz WC)    No matches this session - will compete in gold-medal finals