Togo had gone to the break leading 1-0 after striker Mohamed Kader found himself between the two central defenders and knocked the ball forward using his thigh before lashing his shot against the far post and into the goal.
It was the African debutants' first shot on goal and proved to be a miraculous moment in their country’s footballing history.
The second half began with the Sparrow Hawks looking to hold on for what would have been the biggest upset of the World Cup so far.
However the match turned when Togo defender Jean Paul Abalo received his second yellow card resulting in an early trip to the dressing rooms after he was deemed to have brought down Park Ji Sung as the Manchester United midfielder approached goal.
The foul proved even more costly when Chun Soo Lee converted the first goal from a free kick for the tournament to level the scores.
The Taeguk Warriors then sensed victory and continued to pile forward as they searched for the winner.
Dutch coach Dick Advocaat brought Ahn on at half time as he looked for something different up front and on 72 minutes the move proved to be an inspired one.
From the top of the box the former Perugia striker latched onto a shot which took a slight deflection before rippling the back of the net.
De ja vu for Ahn Jung Hwan
Down a man, Togo had no answers as South Korea rolled on to register their first win of the 2006 tournament and their first win on European soil in a World Cup finals.
In reflection, it is hard to imagine a side having a more chaotic preparation than Togo’s.
The Otto Pfister coaching saga ended with the coach on the sidelines for the team’s first game, what occurred behind the scenes will no doubt emerge in the coming days.
Perhaps Togo's pre-tournament woes can be summed up by the fact that the players had to listen to the Korean national anthem for a second time rather than their own anthem before the mistake was rectified.