Brazil fielded a strong side against the 2002 World Cup semi-finalists, with Neymar, Jo and Hulk pulling the Korean defence all across the field while Dante and David Luiz dealt comfortably with the few times Korea broke into the final third.
Striker Hulk had the first clear chance in the 14th minute, slipped through on goal from Jo's one touch pass, but Korean goalkeeper Jung Sung-ryong rushed out to smother the danger.
Midfielder Ki Sung-yeung picked up the game's first yellow card in the 17th minute after crashing into the back of Neymar, and while the Barcelona forward had to cope with some rough treatment throughout the first half he had the last laugh when he opened the scoring in the 44th minute.
After being fouled just outside the box, Neymar picked himself up then clipped the ball over the wall and past the flailing Korean keeper.
Roared on by a record 65,308 crowd at Seoul's World Cup stadium, South Korea started the second half brightly but quickly found themselves 2-0 down.
Paulinho split the Korean defence wide open and Oscar raced onto the ball, calmly rounded Jung and clipped home with his left foot.
South Korea mounted some sustained pressure late in the second half, but despite the introduction of Bayer Leverkusen forward Son Heung-min the home side rarely threatened Brazilian goalkeeper Jefferson.
Brazil now travel to Beijing to face Zambia in another friendly on October 15.