After a frenetic first round, the knockout stages of the Olympics men's football competition are now set to begin. And even before Saturday's quarter-finals, there have been plenty of upsets to keep crowds across Brazil on the edge of their seats.
With the exits of Argentina and Mexico, the tournament has already been shorn of its last three gold medal winners. Brazil, meanwhile, came roaring back to form after a poor start but face a tough challenge to make the semis on home turf.
The Selecao's all-South American clash against Colombia is one of the highlights of a last eight that should have all the excitement and tension of the group stages.
Portugal vs. Germany
5 p.m. BST/1 p.m. local time, Estadio Mane Garrincha, Brasilia.
Two of the three remaining European teams meet in the Brazilian capital, with both teams having advanced to the quarters unbeaten and with plenty of goals. Portugal, however, will go into the clash as narrow favourites after impressing with two accomplished victories.
Both Argentina and Honduras were dispatched on the way to the knockout stages to clinch early qualification for the new European champions. Germany, meanwhile, were forced to claw back two late draws before a crushing defeat of Fiji sent them through behind South Korea.
Player to watch: Porto starlet Goncalo Paciencia shares a feat with just two other players so far in this Olympics, after scoring in each of Portugal's Group D games. Only Colombia's Teo Gutierrez and Germany's Serge Gnabry have managed such a record, and Germany will have to shackle the 22-year-old to avoid a repeat.
Key battle: Tobias Figuereido vs Gnabry. Portugal, meanwhile, will have to be wary of not one but two Olympic top scorers. While Nils Peterson's five goals all came against woeful Fiji, Gnabry has been on target in every game, and Figuereido will be charged with keeping the rapid Arsenal man under close attention.
Nigeria vs. Denmark
8 p.m. BST/4 p.m. local time, Itaipava Arena Fontenova, Salvador.
Bruised after a comprehensive reverse at the hands of Brazil, Denmark cannot expect to relax against the dangerous Super Eagles. Nigeria may have taken their foot off the gas in their last match, safely qualified, but on the evidence of the opening two games, they are one of the most dangerous attacking units left in the competition.
Player to watch: The Africans like to play fast, physical and direct. The imposing figure of Umar Sadiq dominates the nation's forward line, and with two goals so far, the Roma youngster has proved to be an intimidating prospect as he stands at 6'6". Unfortunately for Denmark, Sadiq is just as proficient on the ground as in the air.
Key battle: Mikel John Obi vs. Jens Jonsson. If the Danes are to stand a chance of progressing, they must keep Nigeria's dynamic forwards under control far better than they managed against Brazil. The best way of doing so is to cut their service under the source: That means Aarhus' Jonsson faces tremendous responsibility in stopping Mikel from crossing the halfway line.
South Korea vs. Honduras
11 p.m. BST/7 p.m. local time, Mineirao, Belo Horizonte.
Anything Honduras achieve from this point forward is merely a bonus, given the supreme effort in escaping from one of the toughest groups in the competition. The Central Americans beat out both Argentina and Algeria to make the knockouts and now face another stiff test in the shape of unbeaten South Korea looms.
With 12 goals, the Asians certainly have firepower, but rapid Honduras may be able to take advantage of their defensive shortcomings on the counter to make Saturday's clash a classic.
Player to watch: His blistering pace may well be giving the five members of the Argentine defence nightmares for days to come. Alberth Elis is a fearsome prospect down the right wing and unlocked the Albiceleste on countless occasions after previously netting against Portugal.
Key battle: Son Heung-min vs. Marcelo Pereira. Honduras, however, are not the only team who pose a significant threat out wide. Tottenham's Son has been in fine form throughout the tournament, while Pereira struggled at times to control the Argentine incursions on his wing.
Brazil vs. Colombia
2 a.m. BST (Sunday)/10 p.m. local time, Corinthians Arena, Sao Paulo.
The South American titans do battle in the final and arguably most enticing clash of this last-eight series. Both teams have had mixed fortunes so far at the Olympic Games but came through with solid final performances to book this repeat of the 2014 World Cup quarter-final match.
The hosts finally discovered their scoring boots in time to destroy Denmark 4-0, a result that will buoy Neymar and Co. as they face their toughest test yet. Colombia are also unbeaten and showed far more resolve in defence to down Nigeria after avoidable mistakes marred their first two outings.
Player to watch: While he may not start, Gremio wonderkid Luan will almost certainly be playing some sort of role in the match after impressing so much against Denmark. The forward gave Brazil much-needed penetration after two awful goalless ties and has the pace and talent to trouble any defence.
Key battle: Marquinhos vs. Teo Gutierrez. No side so far at the Olympics has found a way to stop Sporting's Teo from finding the net, and his goals have been key to the Cafeteros' march to the last eight. Can Marquinhos, highly rated at Paris Saint-Germain, rise to the challenge? The 22-year-old has helped Brazil keep three consecutive clean sheets, but Teo and strike partner Dorlan Pabon represent a whole new challenge.