Koo Ja-cheol helped South Korea to a vital 1-0 World Cup qualifying win over Kuwait, a victory which opened up a three-point lead over their hosts.
Both sides went into Thursday's game in Kuwait City with a perfect record, having won their opening three fixtures in Group G, each without conceding a goal.
However, Koo's powerful header saw Uli Stielike's side move clear of their rivals at the halfway stage of the group.
The away side dominated proceedings early on and opened the scoring after just 12 minutes when Koo headed home a cross from the left.
Kuwait came close to levelling the scoring on a number of occasions, yet their profligacy in front of goal saw them leave empty handed.
South Korea were the better side of the two in the opening stages of the game and were rewarded for their good start inside quarter of an hour.
Park Joo-ho collected the ball down the left after a superb team move and the Borussia Dortmund man sent in a sublime cross for Koo, who beat his marker to the ball before planting a thumping header into the net.
Kuwait then slowly got into the game and first threatened in the 17th minute. Ali Al Maqseed curled in a dangerous free-kick for his attackers, but visiting goalkeeper Kim Seung-gyu rushed off his line to collect the ball before one of the Kuwaiti forwards could connect.
Bader Al Mutawa got a chance to level the scoring shortly before the half-time whistle, yet the experienced attacker hesitated too long, allowing Park to track back and deflect his attempt wide for a corner.
Suk Hyun-jun should have doubled the lead immediately after the restart after escaping the offside trap, but the striker’s left-footed effort went narrowly wide after he evaded Kuwait captain Musaed Neda's last-ditch tackle.
The Koreans got another chance to make it two close to the hour mark when the referee awarded them a free-kick on the edge of the area, only for Kwon Chang-hoon to blast his shot into the wall.
Youssef Nasser should have levelled the scoring in the 65th minute when he chested down a fine ball from the right, but the substitute volleyed wildly off-target from five yards out.
Koo and Kwon both got big chances to put the match to bed, but failed to add a second as South Korea had to settle for a 1-0 win that puts them in a strong position at the group's summit.
