Highlights - Uruguay 2-1 South Korea
Uruguay coach Oscar Tabarez hailed the performance of his side and the quality of Luis Suarez's winning goal in their 2-1 last-16 victory over South Korea.
Suarez scored twice as Uruguay overcame a determined South Korea to book their place in the quarter-finals.
They will face either United States or Ghana in Johannesburg on Friday.
"I think the team put on a display of discipline, maturity and class, and luckily Suarez scored that amazing goal," said Tabarez.
Suarez scored his first goal in the eighth minute as Uruguay seized the initiative in Port Elizabeth, but South Korea fought back and deservedly equalised in the 68th minute through a Lee Chung-Yong header.
Suarez stunner ends South Korean hopes
But having spent much of the game defending, Uruguay were shaken by the goal they conceded and with renewed vigour Suarez had the decisive word 10 minutes from time, creating space for himself on the edge of the area and curling in a superb winner.
"I think Korea had a great match," admitted Tabarez. "Perhaps they weren't lucky and we were, but that's football.
"They [the Koreans] surprised us with their approach and a different style of game. They tired us out.
"This confirms how balanced football has become around the world.
"Our victory was hard fought, it puts us into the quarter-finals and allows us to continue our dream."
Two-time winners Uruguay will be making their first appearance in a World Cup quarter-final since 1970.
Suarez punishes sloppy South Korea
"We are a country of only three million people, we have been a long time looking forward to something like this and now it's happened - we are one of the eight best teams in the world," added Tabarez.
Suarez's two goals takes him to three goals for the tournament.
"Being young, this is the moment I have always dreamed of. This is an unrepeatable moment," said the 23-year-old Ajax striker.
"I can imagine what it will be like back in Uruguay. The truth is they deserve it, all the people who have always been behind us, not to mention our families.
Asked about his winner, he said: "The truth is I didn't even realise the ball was going to go in."