After a much-criticised display in their opening 1-1 draw with Morocco, the five-time world champions underlined the gulf in class with outsiders Haiti, who became the first country to exit this World Cup.Cunha's scruffy goal in Philadelphia gave Brazil the lead midway through the first half, and he struck again as Carlo Ancelotti's side asserted their dominance. Vinicius Junior added a third before the break.Brazil play Scotland in their final Group C game in Miami on June 24. Haiti's first World Cup appearance since 1974 will end after they play Morocco in Atlanta.The Selecao currently have the edge over Morocco for top spot on goal difference. If they finish first, they would face the Group F runners-up -- likely to be the Netherlands, Japan or Sweden -- in the next round.Neymar did not travel with the squad as he continues his recovery from a calf injury, prompting Brazil President Luiz Inacio Lula de Silva to joke he was "working remotely".As promised Ancelotti made changes after the insipid showing against Morocco, bringing United forward Cunha in for Brentford's Igor Thiago and replacing Roger Ibanez with Danilo at right-back.Despite a US government ban which has prevented fans travelling from Haiti, the Caribbean nation received loud support from the sizeable Haitian diaspora, which filled roughly half of the 68,324 crowd.Aggrieved at not coming away with a point from their 1-0 loss to Scotland last week, Haiti coach Sebastien Migne urged his players to embrace the opportunity to play Brazil at a World Cup.With 77 places separating the nations in the FIFA rankings, Brazil quickly took control and thought they had scored when Raphinha fired home, only for the Barcelona winger to be flagged offside. It was a sign of what was to come though and Brazil broke the deadlock on 23 minutes.Cunha sparked the move by winning possession in midfield and, after Vinicius's shot was parried, he reacted quickest to block Hannes Delcroix's clearance to send the ball trickling into the net.Vinicius and Cunha combined again to double the lead, the former slipping his team-mate in behind the Haiti defence to blast in a powerful left-footed shot as he fell to the ground. Brazil lost Raphinha to injury but scored a third before half-time as Vinicius ran onto Lucas Paqueta's floated pass and steered through the legs of Johny Placide. Haiti almost bagged their first World Cup goal in 52 years when Ricardo Ade's glancing header at a corner forced Alisson Becker into a sharp stop, but it was a rare moment of hope.The introduction of 19-year-old Endrick as Ancelotti turned to his bench triggered huge cheers from Brazil supporters, who nearly had another goal to celebrate when substitute Gabriel Martinelli rattled the crossbar. Haiti refused to go down without a fight as Alisson made two late saves to preserve Brazil's first clean sheet in seven outings, turning the page on an underwhelming start to the competition.