Poland's World Cup soccer team moved into the circle of top contenders for the championship tonight as Zbigniew Boniek scored all the goals in a 3-0 rout of Belgium.

In the day's other second-round game, in Madrid, France earned a slim but convincing 1-0 victory over Austria on Bernard Genghini's curving free kick from about 25 yards in the 40th minute. Genghini's left-footed shot curved around a wall of defenders and grazed the inside post past the helpless Austrian goalkeeper, Friedl Koncilia.

The same Belgian team had upset defending champion Argentina, 1-0, and was scored upon only once in its three first-round matches. But tonight Poland evoked memories of its third-place finish in the 1974 World Cup with a multifaceted attack that created several scoring opportunities.

Boniek, who scored two marvelous first-half goals, came close on several other occasions and opened up several holes with passes. Boniek completed the hat trick early in the second half with a goal he started and finished.

The 26-year-old red-headed midfielder began the play with a long run from deep in his own half of the field, then passed the ball into the middle. After two quick passes inside, Boniek sprinted up the middle to receive a short pass as Belgium's defense waited in vain for an offside call from the linesman. The officials let play continue, however, and Boniek had no trouble beating goalkeeper Theo Custers for the third time.

Custers, who plays in Barcelona for the club Espanol, got a rude introduction to Boniek in the fourth minute of his first World Cup match. Veteran right winger Grzegorz Lato, one of the stars of Poland's 1974 team, sprinted down the right side and sent a little backwards crossing pass to Boniek, who sent a hard shot into the top half of the net. Custers was replacing Jean-Marie Pfaff, who was injured last week in Belgium's 1-1 tie with Hungary.

In the 27th minute, the Poles scored a remarkable goal after an intricate combination involving six players. Two pinpoint passes on the right side preceded a long, lofting pass across to Andrezej Buncol on the left wing, who passed it back to Wlodzimierz Smolarek. He chipped it forward to Bnoniek, who sent a soft header past the bewildered goalkeeper.

The Poles varied their game, often using quick, short combinations, then rapidly changing the flow of play with long passes from one side of the field to the other.

The Belgians never gave up, and threatened several times late in the game, including a shot by Jan Ceulemans in the 69th minute that ricocheted off the crossbar. But usually their attacks were wasted, as players tried to make an extra pass or, particularly in the second half, their midfielders took long shots that sailed over the goal.

Poland continued to display an attacking style of play even after the third goal. An apparent fourth goal with 10 minutes left was nullified by an offside call.

Lato, whose fine play was overshadowed by Boniek's world-class performance, was playing in his 100th international match. His coach, Antoni Piechniczek, said the 3-0 victory might have been a present to Lato, but, "as you know, gifts aren't celebrated until after the game is over."

Lato, who appeared with Boniek and the coach at a postgame press conference, said he was happy with the way the Polish team has come along after two scoreless draws in the early stage of the first round. In their last match before tonight, the Poles cut apart Chile, 5-1.

"We hadn't had a chance to train much together or play against any really top teams in the last eight months, so it took us a while to hit stride," Lato said through several interpreters.

Lato had another reason to be happy with tonight's victory. He earns his bread in Belgium, where he plays for FC Lokeren. But he declined to take credit for preparing his team for the game. "The tactics are for the coach to decide," he said with a grin.

The victory means the Poles need only defeat the Soviet Union to reach the World Cup semifinals. Belgium, in order to advance, would have to beat the Soviets by a large margin and hope the Soviets beat the Poles.

Tonight's game was played before a somewhat disappointing but appreciative crowd of fewer than 40,000 fans in the 102,000-seat Nou Camp Stadium.

In the first game, France had control of most of the play, particularly in the first half. The Austrian defenders were unable to contain attacks up the wings, led by Didier Six on the left side and Dominique Rocheteau on the right.

In the second half, France had strong midfield play by Alain Giresse and Jean Tigana, who started in place of injured star Michel Platini. The French had several good scoring opportunities in the first 30 minutes of the second half, and only a lack of concentration around the penalty area stopped them from scoring against the slower Austrians, who appeared tired and drained by the heat.

In the 70th minute, France missed an excellent opportunity as Giresse passed to Rocheteau, whose hard shot had to be cleared from the goal line by Roland Hattenberger.

Austria tested goalkeeper Jean-Luc Ettori only three times, all in the first 20 minutes. One came on a header from Hans Krankl, another when Walter Schachner sent a shot high of the net from directly in front, and a minute later Ettori had difficulty clearing the ensuing corner kick.

Immediately after that play, Rocheteau led several quick counterattacks. In the 29th minute Koncilia was forced to turn away the winger's point-blank shot and almost gave up a goal when he and defender Erich Obermayer nearly collided trying to clear.

Austria had trouble generating any offense in the second half, and often was booed by the crowd, which may have been thinking of the disappointing performance the Austrians and West Germans displayed Friday. Then, the Germans scored an early goal and both teams appeared to coast, since the 1-0 score meant both teams qualified for the second round.