Brazil outplayed Costa Rica for 90 minutes but could only manage a 1-0 victory in their World Cup Group C match in Turin yesterday.
Still, the victory gave Brazil four points from their opening two games and assured them of a spot in the sudden-death second round.
The three-times champions joined Cameroon, Italy, Czechoslovakia and West Germany, who already had clinched second-round berths.
Brazil scored the only goal in the 33rd minute, when striker Muller's hooked shot flew past goalkeeper Luis Conejo after it was deflected off defender Mauricio Montero. Brazil created a plethora of chances throughout the one-sided contest, but were foiled either by the dogged Costa Rican defence or the athleticism of Conejo.
Concjo's performance kept alive Costa Rica's chances of advancing in the tournament. The Central American nation has two points from two games after beating Scotland 1-0 in its opener.