South Korea took their time to get going before finally overcoming the resistance of 10-man Togo.
Lee Chun Soo (right) scored South Korea's equaliser
The one moment of real quality in the first half came when Togo's Mohamed Kader controlled the ball on his thigh and lashed home a fine shot.
Kader nearly made it two after the break before Jean-Paul Abalo's second booking saw him sent off.
Lee Chun-Soo curled in the resulting free-kick and Ahn Jung-Hwan's deflected strike won the game for South Korea.
Sweltering temperatures beneath a closed roof ensured the game got off to a sluggish start, with little real incident at either end in the early stages.
The deadlock was broken just past the half hour with the first moment of real quality from either side.
Kader sprinted forward, controlled the ball beautifully with his thigh and shot low into the bottom corner from the edge of the box.
Cho Jae-Jin and Lee Eul-Yong tried long-range efforts as South Korea tried to get back into the game, but they still seemed dazed at having gone behind.
Junior Senaya's free-kick almost doubled Togo's lead just before half-time, drawing a fine save from Lee Woon-Jae.
Kader showed neat footwork as he nearly added a second early in the second half, before Jean-Paul Abalo was sent off for a foul on Park Ji-Sung, and Lee Chun-Soo's perfectly judged free-kick from just outside the box drew South Korea level.
Cho Jae-Jin narrowly missed connecting with a diving header as the pace of the game picked up following the second goal, with Moustapha Salifou having a couple of chances for Togo.
But it was Korean substitute Ahn Jung-Hwan who was next to find the net, turning on the edge of the box to fire a deflected shot high into the roof of the net.
Emmanuel Adebayor wasted a great chance for Togo when he fouled his marker when in a scoring position, as Korea took a tight grip on the game.
Togo battled valiantly, but ultimately South Korea's one-man advantage proved decisive.
South Korea: Woon-Jae Lee, Young-Chul Kim, Choi, Jin-Kyu Kim (Ahn 45), Young-Pyo Lee, Song, Ji-Sung Park, Eul-Yong Lee (Nam-Il Kim 68), Ho Lee, Chun-Soo Lee, Jae-Jin Cho (Sang-Sik Kim 83).
Subs Not Used: Baek, Won-hee Cho, Chung, Do-Heon Kim, Dong-Jin Kim, Yong-Dae Kim, Young-Kwang Kim, Chu-Young Park, Seol.
Booked: Young-Chul Kim, Chun-Soo Lee.
Goals: Chun-Soo Lee 54, Ahn 72.
Togo: Agassa, Nibombe, Tchangai, Assemoassa (Forson 62), Abalo, Salifou (Aziawonou 86), Cherif-Toure, Romao, Senaya (Toure 56), Mohamed, Adebayor.
Subs Not Used: Agboh, Akoto, Dossevi, Erassa, Malm, Obilale, Olufade, Tchagnirou, Atsou.
Sent Off: Abalo (53)
Booked: Abalo, Romao, Tchangai.
Goals: Mohamed 31.
Ref: Graham Poll (England).
Fifa man of the match: Ahn Jung-hwan
South Korea have won their World Cup opening match for the second consecutive time. In 2002 they beat Poland 2-0. Before 2002 they had never won their initial fixture, losing four and drawing one. Togo's defeat leaves debutant teams winless at the 2006 World Cup. Leo Beenhakker's Trinidad & Tobago is the only debutant to clinch a point so far. Angola, Ghana and the Ivory Coast all lost their opening match. Ukraine are yet to play Spain.
South Korea have conceded the first goal in 17 of their 22 World Cup matches. Before today they had won just once after going behind from the opening whistle. South Korea became the second team at this tournament to win after going behind 1-0, following Australia's example.
Abalo Dosseh (Togo) became the second player to be sent off at this World Cup, following Avery John (Trinidad & Tobago).