Hosts Brazil opened the Confederations Cup with a comfortable 3-0 win over Japan on Saturday but the occasion was marred when police fired teargas at protesters outside the Mane Garrincha National Stadium.
New Barcelona forward Neymar was a constant menace throughout and got his country off to the perfect start on three minutes when he volleyed home a sensational effort from 25 yards.
And Brazil wrapped up a convincing success in stoppage time when substitute Jo raced onto Oscar's pass and coolly slotted home.
Some fans in the 67,000 crowd had to be treated for the affects of tear gas fired by riot police at demonstrators outside the stadium.
Inside, the football crowd witnessed 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 Selecao came into the match looking to convince a global audience they are back on the right track in what many regard as a dress rehearsal ahead of next summer's World Cup finals.
Much of the expectation inevitably centres around Neymar, hailed as the country's icon and the key to their dreams of glory.
It is a vast burden for a 21-year-old to carry but he took just three minutes to shrug it off, showing why he is regarded by many as the heir to Lionel Messi's crown as the best player on the planet.
The former Santos forward latched onto Fred's chest down from Marcelo's cross and unleashed a stunning volley into the top right-hand corner from 25-yards out to get the hosts off to a flyer. It was the number 10's 21st goal for his country and arguably his finest to-date.
It set the tone for a first half dominated by the hosts, but Japan did have their moments.
Honda twice brought fine saves out of Julio Cesar in the Brazil goal with shots from distance while at the other end Hulk saw a powerful effort crash into the near-post side netting.
The Asian Cup winners survived one or two moments when the Selecao mistimed the final pass on the break and they were breathing a huge sigh of relief again on 42 minutes.
A sweeping Brazilian counter attack presented Hulk with a clear sight of goal but the Zenit striker saw his low shot brilliantly palmed to safety by Eiji Kawashima.
Japan did make a bright start to the second period but saw all of their hard work vanish within three minutes when Paulinho controlled Alves' cross before drilling in a fierce shot that seemed to go through the dive of Kawashima.
Substitute Ryoichi Maeda went close to notching a consolation for the Samurai Blue with a low strike that brought a fine save out of Cesar.
But Brazil saw out the final moments at a canter and netted a third on the break in injury time, with Jo racing clear to score his first ever goal for his country.
MAN OF THE MATCH
Neymar, Brazil: Capped a superb all-round display with a sensational opening goal that put his team on the road to victory.
BRAZIL: Cesar 6, Alves 6, Luiz 6, Thiago Silva 6, Marcelo 7, Luiz Gustavo 6, Oscar 6, Paulinho 7, Fred 6, Hulk 7, Neymar 8.
Subs: Lucas 5, Hernanes 5, Jo 5.
JAPAN: Kawashima 7, Honda 7, Nagatomo 7, Uchida 6, Endo 6, Kiyotake 5, Okazaki 5, Kagawa 5, Konno 6, Hasebe 5, Yoshida 5.
Subs: Maeda 5, Hosogai 5, Inui 4.