Australia had one foot in next year's World Cup finals in South Africa after beating Uzbekistan 2-0 on Wednesday, while South Korea scored a late winner to down rivals North Korea 1-0 and wrestle back their Group Two lead.
The win in Sydney moved Australia two points clear of Japan in Group One and the Socceroos will become the first team to qualify for the 2010 finals if Bahrain and Qatar draw their match in Manama later on Wednesday.
South Korea snatched the group lead from their fierce political foes with a free kick on the right from Kim Chi-woo with three minutes left, which floated past a hoard of leaping players into the far corner.
Victory put the 2002 World Cup semi-finalists top on 11 points, with North Korea one point behind having played one more game.
Australia failed to make an impact in a dour first half but began to attack after the break and took the lead in the 66th minute with a headed goal from the unmarked Josh Kennedy.
Harry Kewell sealed the win with a 73rd minute penalty, giving Australia 13 points from five matches, with no goals conceded.
"There was a lot of pressure on today's game because we knew we had to win the game," Australia captain Lucas Neill said in a television interview.
"It was there for us to win but we've sent a statement out to the rest of the group now and possibly the world that we might be the first team to qualify."
South Korea were frustrated by their defensively solid neighbours throughout the match and stepped up a gear after an entertaining but fruitless first half.
They almost fell behind soon after the break when Jong Tae-se's header, which appeared to have crossed the line, was ruled out.
South Korea's frustrations were compounded when they squandered a series of golden scoring opportunities, with Lee Keun-ho twice the guilty party.
Park Chu-young's 66th-minute blocked shot landed at Lee's feet and he tamely struck the ball into the hands of the goalkeeper.
In an almost identical move two minutes later, Park slotted the ball through to the unmarked Lee, who fired his shot at the keeper again before collapsing to the floor in frustration.
South Korea finally got their goal in the 87th minute to bag the three points and make qualification for their seventh-successive finals almost a certainty.
A resurgent Saudi Arabia continue their push for their fifth finals in a row when they meet bottom side United Arab Emirates in Riyadh later Wednesday.