Korea Republic came from two goals down to beat historic rivals Japan 3-2 to reach the semi-finals of the AFC U-19 Championship and also book a place in next year's FIFA U-20 World Cup.

The 11-time champions will clash with northern neighbours DPR Korea, who stunned hosts China 2-0 in front of 30,000 fans at Zibo Sports Center and will play at the same venue on Thursday.

Australia knocked out holders UAE 4-2 in extra-time in their quarter-final match and Saudi Arabia also needed extra-time to beat Uzbekistan 2-1. Australia and Saudi Arabia will clash in the first semi-final on Thursday, which will be held at Linzi Stadium.

All the semi-finalists were in celebratory mood as the four nations will compete at Colombia 2011, two years after Korea Republic and UAE reached the quarter-finals in Egypt and Uzbekistan and Australia exited in the group stage.

The showdown between Korea Republic and Japan in Linzi was a rematch of the 2008 quarter-finals, when the Koreans won 3-0. This time, Japan raced into a two-goal lead with a brace from Hiroshi Ibusuki, the 1.94-metre Spain-based striker, who netted in the 13th minute and from the penalty spot in the 30th minute.

The Koreans responded immediately as midfielder Kim Kyung-jung halved the deficit a minute later. They added two quick goals before half-time through defender Hwang Do-yeon in the 44th minute and a free-kick by forward Jung Seung-yong in the first minute of added time.

"Our team played thinking that the match was the final," said Korea Republic coach Lee Kwang-jong. "Winning not only means we have a ticket to the U-20 World Cup but also means we're through to the semi-finals. Now, we have a very good chance to get to the final."

"We started the match badly by giving them two goals, but managed to come back and it was especially important to go ahead before half-time."

The win sets up the tantalising prospect of Korea Republic, knocked out in the semi-finals in the past two events, taking on 2006 champions DPR Korea.

"DPR Korea are the same nationality as us," Lee said. "We are one people and one family, but in the world of football one team must win so we'll try our best."

DPR Korea disappointed a massive crowd as they knocked out China with early second-half goals by Jong Il-gwan and Pak Song-chol, his third of the tournament. The result exacted revenge for a defeat to China at the same venue in a qualifying match last November.

"Last year, China beat us and at the time we concentrated on attacking. We lost but we gained some experience," said DPR Korea coach Yun Jong-su.

"This time we concentrated on our midfield and defence. We'll do our best in the semi-finals. Each player's fitness is different and we played hard in the group stage, so the team were a bit tired."

Australia also gained revenge for their loss to the UAE in the 2008 semi-finals with a thrilling extra-time victory.

Striker Kerem Bulut netted a sixth-minute opener before Ahmed Khalil equalised through a 23rd-minute penalty. Mustafa Amini put Australia ahead again with a fine shot in the third minute of the second half, but Khalil, who scored against Australia two years ago, levelled six minutes from time with his sixth goal of the tournament.

Despite that setback, Australia restored their lead in the second minute of extra-time when substitute Matthew Fletcher crossed for Matthew Leckie to stab home from close range. Twelve minutes later Fletcher converted from close range to seal Australia's passage to the semi-finals.

"It was a very difficult match. You could see it was like a final because both teams were very nervous at the start of the game," Versleijen said.

"When we came into this tournament we thought we could possibly win. But we're not the only ones who have this thought and in the semi-finals there are four good teams."

Saudi Arabia beat Uzbekistan to make up for their disappointment as hosts two years ago when they were knocked out in the quarters and missed out on last year's FIFA U-20 World Cup.

Midfielder Abdumutallib Abdullayev gave Uzbekistan a sixth-minute lead but Saudi Arabia went on to dominate the game and hit the woodwork twice before Abdullah Otayf finally equalised in the 83rd minute. Fahad Al Johani then netted the winner five minutes into the first additional period.

This year's AFC U-19 Championship has so far attracted over 300,000 spectators to the matches at Zibo Sports Center and Linzi Stadium. The semi-finals will be held on October 14 and the final will be held at Zibo Sports Center with the final on October 17.