BRASILIA — Host Brazil opened the Confederations Cup with a comfortable 3-0 win over Japan Saturday although the occasion was marred when police fired teargas at protesters outside the Mane Garrincha National Stadium. A stunning third minute goal from Neymar set Brazil on its way before Paulinho ended Japan's challenge by adding a second three minutes into the second half of the Group A match. Substitute Jo completed the scoring in stoppage time as the host, playing its first competitive match since the Copa America nearly two years ago, dealt competently with the Asian champion which created some nice moves in midfield but lacked punch. Some fans in the 67,000 crowd had to be treated for the affects of tear gas fired by riot police at the protester who are angry at the cost of building stadiums for the tournament and next year's World Cup. Inside, the football crowd was treated to a competent Brazilian victory by Luiz Felipe Scolari's men who are looking for a third successive Confederations Cup success after winning the tournament in 2005 and 2009. The game came alive after three minutes when Neymar scored a stunning goal, smashing home a right foot shot from the edge of the box after a long cross from Marcelo was chested down by Fred. That lifted the massed ranks of the fickle yellow-shirted home crowd but they began to show their impatience soon enough as Brazil failed to build on that early goal and Japan came into the match with Keisuke Honda in particular making inroads in midfield. Japan, which started with only Shinji Okazaki as the nominal front man, began to look increasingly dangerous with some incisive moves through the middle but it never seriously troubled goalkeeper Julio Cesar. Despite allowing Japan some clever passing play, Brazil also showed some flashes of flair. Neymar produced a little shimmy on the left, but failed to get past his marker, while Hulk, ploughing his way up and down the right wing like a farmyard tractor, crashed a well-struck shot into the side netting. Fred forced Eiji Kawashima into a fine one-handed save with a low snapshot after a floated cross from Neymar two minutes before the break. Three minutes after the break though, Brazil did find the net again when Paulinho met Dani Alves's cross and blasted home. In a largely uneventful second half, Brazil coped easily with what limited danger Japan put in its path before Jo finished off a counter-attack to give them a convincing win. The match was the first international game to feature goal-line technology although it was not called into action. — Reuters