South Korea are on the brink of making another World Cup finals appearance after scraping a 1-0 victory over Uzbekistan in a top-of-the-table qualifying clash in rainy Seoul on Tuesday.
An entertaining match was settled by an own goal from Akmal Shorakhmedov just before halftime, the Uzbek defender heading Kim Young-gwon's cross from the right past his helpless goalkeeper.
The Koreans now have 14 points from seven matches in Group A of Asian qualifying, three clear of the Uzbeks with Iran on 10 from six games with only the top two guaranteed a place at Brazil 2014.
Iran host Lebanon later on Tuesday and a shock defeat for the home side would mean Korea qualifying ahead of their final fixture against Carlos Queiroz's side in Ulsan next week.
The Koreans need only a point against Iran to qualify but their strong goal difference means even a 1-0 defeat against the West Asians is likely to be enough unless the Uzbeks can score a six goal win over Qatar in their final fixture, also on Tuesday.
"Tonight's match was the greatest roadblock in our way to the World Cup and we managed to overcome it," South Korea coach Choi Kang-hee told reporters.
"We can prepare the match against Iran feeling less burdened. But still, we will do our best."
The Koreans had the better chances on a slick surface in Seoul on Tuesday with towering striker Kim Shin-wook causing the visitors numerous problems in the air.
A flicked header by the forward gave Asian player of the year Lee Keun-ho a fantastic chance to open the scoring in the 11th minute but the tricky forward sliced his shot hopelessly wide from six metres.
The Uzbeks also played well although they struggled in the final third, striker Ulugbek Bakayev offering their best chance with a fizzing shot from distance that was palmed away.
The Koreans always looked more likely to score and they took the lead three minutes before halftime when Kim Young-gwon cut inside on to his left foot and his inswinging cross was flicked in by Shorakhmedov at the near post.
The Uzbeks, who are at home to Qatar in their final match next Tuesday, took the game to the Koreans in the second half.
They threw on substitute forwards Aleksandr Geynrikh and Sanzhar Tursunov but were still unable to create clear-cut chances despite the Koreans tiring in the heavy conditions.
The home side, who stuttered to a 1-1 qualifying draw in Lebanon last week, held out for the three points which left them on the verge of their eighth successive World Cup finals appearance.
"I emphasised to them this is the game of mental strength and one goal will decide everything," Choi said.
"I am grateful that the players did not lose concentration till the very end despite the difficult situation."