MANAGUA, NICARAGUA, AUG. 12 -- Nicaraguans gathered around their radios today to listen to the progress of a major confrontation with the United States.

"We're getting kicked all over the field," said 11-year-old David Lopez glumly as he listened to first reports of the encounter.

Defense Minister Gen. Humberto Ortega also was following the action closely, having personally sent the Nicaraguan side off to the struggle with words of exhortation and a reminder of the "great responsibility" they carry.

Today's confrontation, heavy with implications for national honor though it may be, was fought not in the jungles of Central America but on a baseball diamond in Indianapolis.

The United States, which opened a 6-0 lead in the first inning, went on to win 18-0, with the game mercifully called after seven innings. {Story on Page D1.}

Baseball has overshadowed political developments here in the aftermath of a Central American peace agreement signed Friday in Guatemala City. Yesterday, as President Daniel Ortega, Humberto's brother, was meeting with leaders of the Roman Catholic Church and opposition political parties to invite participation in a Commission of National Reconciliation, the state radio was broadcasting the game between Nicaragua and Canada. The Canadians won, 10-5.

At stake is a medal for the Nicaraguan national baseball team in the Pan American Games, an accomplishment that would qualify this country for the Olympic baseball competition in South Korea next year.

But the prospect of an Olympic berth for Nicaragua appears to be dim after two straight losses and a tough game against Cuba still to come.

In the years since U.S. Marines occupied Nicaragua in the 1920s and 30s, beisbol has been the country's national sport, and fans include members of the Sandinista government like the defense minister. He recently pitched nine innings for an Army team in a victory over Nicaraguan sportswriters and commented on the national team's chances afterward.

"This team has awakened the greatest expectations of any in the last several years, and as a result its responsibility is greater," Ortega said. He said that after Cuba and the United States, considered the strongest teams in the Pan American Games, the Nicaraguan team should come in third for a bronze medal. The team needs to finish in the top four to qualify for Seoul.

Asked if he would like to have been a baseball player himself, Ortega told the Sandinista party newspaper Barricada, "I am a ballplayer. Didn't you just see me pitch nine innings, with control? I could be the eighth pitcher on the staff of the national team." Lately it has needed all seven hurlers.

Baseball seems to cross political boundaries here, with both pro- and antigovernment Nicaraguans rooting for the national team.

"The boys are very nervous," Nicolas Lopez, 57, said of the Nicaraguan players as he listened to the radio while working in his furniture shop in a working-class district of Managua. "There are a lot of expectations for them, and if we win it will be tremendous." But he and his son David lamented as the American runs crossed that plate that the Nicaraguan team did not have much of a chance.

Unhappy about the country's economic situation and the military draft that recently took away his oldest son, Lopez said he thought some Sandinista leaders were just pretending to be baseball fans "to show they are with the people."

A measure of the role of baseball here was the Sandinistas' decision to install lights in the national stadium -- renamed the Rigoberto Lopez Stadium in honor of the assassin of president Anastasio Somoza Garcia in 1956 -- as one of the revolutionary government's first projects. But typical of the suspiciousness of many Managuans is the widely held belief that the metal scaffoldings for the lights are really meant to hold rocket launchers.

Nicaragua long has been known as a baseball powerhouse in Central America, perennially winning the regional championship. Last year the second-string national team emerged victorious in the Central American championship tournament held in Tegucigalpa, Honduras, despite efforts by Nicaraguan rebel exiles to disrupt play at one point.

In one of the ironies that characterizes baseball in Nicaragua, the team took away a trophy that had been donated by the U.S. Embassy.

Earlier this year, Soviet enthusiasts visited here as part of a crash program to learn to play baseball before it becomes an official Olympic sport. The Soviet team, consisting mainly of gymnasts for some reason known only to the Russians, had made a similar visit to Japan, but the players look like they have a long way to go.

While Nicaragua has its own leagues, the World Series usually rivets the country's attention in the fall. The favorites of many Nicaraguans are the Yankees, but the Dodgers have many fans here because of their Latino players.

Currently one Nicaraguan, ex-Baltimore Oriole pitcher Dennis Martinez, now 7-1 for the Montreal Expos, carries his country's standard in the majors, and his games are followed closely in the press.