Brazil became a bigger favourite than ever to win the men's football tournament after the British were eliminated in the quarterfinals, following in the footsteps of other top contenders such as Spain and Uruguay.
Even the Brazilians admit they are in good position, but they are not taking anything away from the South Korean team it will have to face on Tuesday.
Brazilian players said they were surprised by how the South Koreans never caved in against the hosts, sending them home after extra time and penalties in the quarters.
"South Korea is a team which runs a lot all the time and will never give up," Brazil captain Thiago Silva said. "Even during the extra time, when you expected them to get a bit more tired, they kept running and going after the goal to advance."
The South Koreans held on as the British pressed forward backed by the home crowd in Cardiff, Wales, drawing 1-1 after regulation and extra time and then advancing 5-4 in a penalty shootout.
"South Korea has a very intense game, their players can keep up the pace during the entire match," Brazil coach Mano Menezes said.
Brazil barely escaped being upset in its own match, needing to twice rally from behind against a Honduras team which played a man down from the 33rd minute in Newcastle, England. Brazil won 3-2 with two goals by Leandro Damiao and one by Neymar.
Brazilian players finished the match and went straight to the hotel to watch the late quarterfinal between South Korea and Britain, hoping to take a close look at their next opponent.
In addition to the South Koreans' strong physical condition, Silva said the Asians also know how to play simple and hardly make mistakes, giving few chances to their opponents to get near their area.
"They move the ball around really well," the Paris Saint-Germain central defender said. "They rarely miss a pass and they are intelligent getting into position up front."
Tuesday's semifinal should provide a matchup between attack against defence at the Old Trafford. Brazil has scored 12 goals in its first four matches, while South Korea's defence has conceded only two. The Koreans have lacked much offensive power, though, scoring only three goals, while Brazil's defence allowed five.
Brazil is the only team which won all of its four matches, while South Korea will play in the semifinals after winning only once in regulation. It beat Switzerland 2-1 in the group stage, when it advanced with five points behind group-winner Mexico. The Mexicans are playing Japan in the other semifinal.
"We will have to play with the same determination that we have played so far," Silva said. "That kind of determination has taken us to the semifinals already."
Brazil's men's team has won four Olympic medals, but none of them were gold. It earned silver in 1984 and 1988, and bronze in 1996 and 2008. It is the only significant football competition the five-time world champions haven't won.
Brazil arrived as one of the top favourites for the gold because many of its top players make the tournament's under-23 age limit, including Neymar, Oscar and Alexandre Pato. Each nation can also use three players over that age.
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