Todd Eckenrode, 29, a golf course architect from Corona del Mar, shot 67 at Torrey Pines South to take medalist honors at the U.S. Amateur Public Links championships with a 7-under 137 total. Match play begins today. . . . Mike Lavery, who will be a junior at Irvine High School this fall. shot 4-under 68 to lead after one round of the American Junior Golf Assn. tournament in Nashville. . . .