Hosts Brazil finally launched their campaign for Olympic gold as sought after starlet Gabriel Barbosa struck twice to defeat Denmark 4-0 on Wednesday, as two-time champions Argentina bowed out of Rio 2016.

Barcelona star Neymar is still yet to hit the net, but played the role of facilitator as Gabriel Jesus and Luan were also on target to end a run of over 200 minutes without a goal after stalemates with Iraq and South Africa got their campaign off to a faltering start.

Victory sealed top spot in Group A to set up a quarter-final meeting with Colombia on Saturday.

Crisis-hit Argentina didn't survive a sluggish start as they were dumped out by Honduras, whilst 2012 gold medallists Mexico were also sent packing.

Freiburg striker Nils Petersen scored five times as world champions Germany smashed Pacific islanders Fiji 10-0 to seal their place in the last eight behind South Korea, who beat Mexico 1-0 thanks to Kwon Chang-hoon's stunning strike in Brasilia.

Colombia moved into the knockout stages by beating Nigeria 2-0 with captain Teo Gutierrez and Dorlan Pabon on target.

The Africans had already done enough to top Group B rendering Japan's 1-0 win over Sweden meaningless.

Denmark progressed despite defeat in Salvador as Iraq and South Africa played out a 1-1 draw in the other Group A match.

Portugal secured top spot in Group D with a 1-1 draw against Algeria in Belo Horizonte to set up a last eight meeting with Germany on Saturday.

South Korea face Honduras and Nigeria take on Denmark in the remaining quarter-finals.

Manchester City's new recruit Jesus said before the game he didn't care if Brazil's sought after goal came "off a belly or a bum" and A Selecao got the bit of fortune they needed when Barbosa's opener trickled into the far corner off his shin.

Jesus and Luan put the game beyond doubt either side of half-time before Barbosa, who has been linked with a move to Premier League champions Leicester City, fired in a deflected fourth 10 minutes from time.
                  
'Mafia'                  
                  
Argentina needed to win to secure a place in the quarters due to their inferior goal difference with the Hondurans after both had lost to Portugal and beat Algeria in their opening two group matches.

However, the Central Americans sprung a huge surprise as Antony Lorenzo's penalty 15 minutes from time put them in front in Brasilia and, despite Mauricio Martinez's equaliser deep into stoppage time, Argentina bowed out in embarrassing fashion.

The Albiceleste's chances were severely hampered by chaotic preparation for the Games.

Coach Julio Olarticoechea, who had been coaching the Argentine women's team, was put in charge just weeks before the tournament began after Gerardo Martino resigned citing power squabbles at the Argentine Football Association (AFA) and clubs not releasing players for the Olympics.

Legendary former player Diego Maradona has branded AFA's management a "mafia," and raged against football administrators in Argentina once more on Wednesday.

"Honduras can't beat us. A country for which I have a lot of respect, but they play baseball they don't know anything about football," he told Radio La Red.

Argentina's conquerors in the 2014 World Cup final Germany remain on course for another Brazilian party at the Maracana on August 20 as they brushed aside the hapless Fijians in Belo Horizonte.

Fiji benefited from New Zealand's disqualification for fielding an ineligible player to qualify for the Olympics and conceded 23 goals over the course of their Group C games having also been smashed 8-0 and 5-1 by South Korea and Mexico respectively.

Arsenal winger Serge Gnabry also scored twice to lead the competition's scoring charts along with Petersen on five.