A hat-trick from Gonzalo Higuain, the first of the competition, inspired Argentina to their second straight victory as Diego Maradona's side took a huge stride towards the knockout stages.
An own goal from the unfortunate South Korean Chu-Young Park gifted Argentina the lead early on before Higuain took control.
The defensive Koreans were undone in the 17th minute when Chu-Young diverted Lionel Messi's free kick into his own goal at Soccer City in Johannesburg.
Argentina doubled their advantage in the 33rd minute when Higuain scored his first with a neatly taken header at the back post that looked to have put his side in total command.
Chung-Yong Lee offered the underdogs a glimmer of hope, however, when he capitalised on a woeful mistake from Martin Demichelis to pull a goal back on the stroke of half time.
The Bayern Munich defender was found wanting and robbed of possession by the midfielder, who beat Argentina goalkeeper Sergio Romero with a calm finish.
The game was played out to the backdrop of Maradona rowing with his Korean counterpart Huh Jung-Moo on the touchline as the duo clashed for the first time since Jung-Moo man-marked Maradona in the 1986 World Cup - when the South Americans came out on top.
Despite the gift offered to the Koreans, Maradona's side never looked like relinquishing their lead this time either.
It seemed more a case of how many goals they would win by as they continued to dominate after the break.
Jung-Sung Ryong produced a string of fine saves to somehow keep his side in the contest, the best of which saw him deny the impressive Carlos Tevez and Higuain in quick succession.
But Jung-Moo's side refused to give up and wasted a golden chance to equalise just before the hour mark.
Chung-Yong Lee broke swiftly down the right before sending Yeom Ki-Hun clean through on goal, but with just Romero to beat he fired wide and his chance to become a hero had gone.
Higuain then took charge, producing two clinical finishes in the final 14 minutes as Argentina cruised to a comfortable win.
Argentina (4-3-3): Romero; Gutierrez, Demichelis, Samuel (Burdisso, 23), Heinze; M Rodriguez, Mascherano, Di Maria; Messi, Tevez (Aguero, 75), Higuain (Bolatti, 82)
South Korea (4-4-2): Jung Sung-Ruong; Oh Beom-Seok, Cho Yong-Hyung, Lee Jung-Soo, Lee Young-Pyo; Lee Chung-Yong, Ki Sung-Yeung (Kim Nam-Il, 46), Kim Jung-Woo , Park Ji-Sung; Park Chu-Young (Lee Dong-Gook, 81), Yeom Ki-Hun.