With much of the planet watching, defending champion Germany took on underdog Bolivia on Friday to kick off the World Cup. A four-year buildup, scores of qualifying matches and last-minute lineup tinkering by the 24 national teams preceded the world's biggest sports event, being held on unfamiliar territory in nine U.S. cities. An estimated 750 million people in some 180 countries tuned in for the first game in the month-long world championship, World Cup organizers said. Guests among the sellout crowd at Soldier Field in Chicago included President Bill Clinton, Germany's soccer fan chancellor Helmut Kohl and Bolivian President Gonzalo Sanchez de Lozada. "Our time has come," chief U.S. organizer Alan Rothenberg told the crowd during a colorful opening ceremony featuring pop music and native dances of the team's countries. Clinton, in a brief message, welcomed the contest to the United States. No defending champion has ever won the opening match, but Germany has lost only one of its 12 openers -- against Algeria, 2-1, in Spain in 1982. Spain was favored against South Korea in the other clash on the 52-game tournament's opening day, set to start a 6:30 P.M. in Dallas. Germany is seeking to become the first nation to win the World Cup four times. Germany, Brazil and Italy have won the most coveted title in sports three times. The Germans can also become the first nation to repeat as champions since Brazil in 1962. Germany, which won in 1954, 1974 and 1990, is the dominating power of the last two decades. It reached the finals in four of the last five tournaments, with two titles and two runnerup finishes. Bolivia went into its first World Cup finals since 1950 with no win and no goal on its record. Italy, Ireland, the United States, Switzerland, Romania and Colombia got their final practices before Saturday's three games. Italy, one of three teams shooting for a record fourth World Cup title, will test its potential against Ireland, a tough, physical opponent, at Giants Stadium, East Rutherford, N.J. Italian coach Arrigo Sacchi and his Irish counterpart, Jack Charlton, said a good start in the competition can be decisive under a new system awarding three points for a win in first-round games instead of two points as in the past. At the Rose Bowl in Pasadena, California, Colombia's status as a tournament favorite will be put to an early test by Romania. The South Americans qualified for the World Cup without losing a game and its runup included a 5-0 victory over Argentina. But Romania is hardly a pushover. For the United States, its first appearance as host -- against Switzerland -- is immediately critical. As Romania and Colombia loom later in the first round, Saturday's game at the indoor Pontiac Silverdome is likely to be the best shot for victory.