Hosts Great Britain won through to the Olympic men's football quarter-finals after Daniel Sturridge's goal secured a 1-0 win over Uruguay at Cardiff's Millennium Stadium on Wednesday.
Stuart Pearce's men will be back at the Millennium this Saturday to face South Korea in the last eight ahead of a possible semi-final against pre-tournament favourites Brazil at Old Trafford on Tuesday.
But had Gaston Ramirez's injury-time effort, which struck the crossbar, been a touch lower, Uruguay would have had a draw.
Instead defeat saw Uruguay, whose captain Luis Suarez was jeered throughout after the Liverpool striker was banned last season for racially abusing Manchester United's Patrice Evra, eliminated after Chelsea striker Sturridge scored in first half stoppage time.
Neat approach play by Joe Allen saw the Swansea star weave his way through the Uruguay box before driving a low cross which Sturridge, whose Olympic hopes were in the balance after he was diagnosed with viral meningitis just a few weeks before the tournament, turned in from close range.
Victory saw Britain follow their women's team into the knockout stages after both sides had entered the Olympics against a backdrop of fierce opposition from Celtic countries fearful of losing their football independence.
"We played some outstanding football," said Stuart Pearce, coach of the first British men's team to compete at an Olympics for more than 50 years.
"Overall, I'm delighted we beat a good Uruguay side 1-0," the former England full-back added,
Brazil saw Porto star Alex Sandro sent off as they overpowered New Zealand 3-0 at Newcastle's St James' Park.
By the time he was dismissed for a second bookable offence, Internacional striker Leandro Damiao had sent the South Americans on their way into the knockout stages.
The 23-year-old set up midfielder Danilo for the opener and then claimed his second goal of the tournament before the break, with Tottenham's Sandro seal a victory which will see his side return to St James' on Saturday.
Five-times world champions Brazil have yet to win Olympic gold and coach Mano Menezes was concerned Alex Sandro's dismissal could harm their chances this time around.
"Losing Alex Sandro is a great worry. The first yellow card was undeserved."
He added: "Gold is still a long way away. We will only think about gold if we get to the final."
Now Brazil will play Honduras after the Central Americans held Japan to a goalless draw in Coventry to reach the last eight of an Olympic tournament for the first time
"Everyone was talking about Spain and we have beaten them with all respect," said Honduras's Jose Mendoza.
"Now we have Brazil and we going to try our best. We all know that will be difficult but we have done Spain. Let's see."
Egypt also reached the last eight with a 3-1 win over Belarus at Glasgow's Hampden Park and will face Japan at Old Trafford in the first of four quarter-finals all being played on Saturday.
Mexico topped Group B with a 1-0 win over Switzerland at the Millennium secured by Oribe Peralta's second-half goal while South Korea advanced into the quarter-finals despite a goalless draw against Gabon.
Now Mexico will play Senegal after the African secured a 1-1 draw against the United Arab Emirates thanks to a Moussa Konate goal that cancelled out Ismaeil Matar's opener at the City of Coventry Stadium.
Meanwhile Spain's miserable tournament ended with a goalless draw against Morocco at Old Trafford.
Britain's goalkeeper Jack Butland celebrates winning the London 2012 Olympic Games men's football match between Great Britain and Uruguay at the Millennium Stadium in Cardiff, Wales.
Uruguay's striker Luis Suarez takes a shot past Britain's defender Steven Caulker in the London 2012 Olympic Games men's football match between Britain and Uruguay at the Millennium Stadium in Cardiff, Wales. Hosts Great Britain won through to the Olympic men's football quarter-finals after Daniel Sturridge's goal secured a 1-0 win over Uruguay.
Brazil's defender Alex Sandro (R) vies with New Zealand's forward Marco Rojas during the London 2012 Olympic Games men's football match between Brazil and New Zealand at St James' Park in Newcastle, north-east England. Brazil beat New Zealand 3-0.