Lee, world No. 8, began the day by defeating Daniel Rezende Xavier of Brazil by the set score of 6-2 (28-22, 30-27, 27-28, 28-26).

Each set consists of three arrows. A set win is worth two points and a draw is worth one point. The first archer to reach six points is the winner.

Next, Lee beat Miguel Alvarino Garcia of Spain 7-1 (28-27, 29-23, 29-29, 28-27).

On Monday, Kim Woo-jin, the first South Korean man to enter the individual event, was knocked out in the round of 32. Ku Bon-chan, the third member of the team, will take the range on Wednesday.

Lee said Kim's early departure disappointed him, too, but it won't affect his performance.

"The goal of our team was to sweep the individual gold, silver and bronze medals," Lee said. "Since this is the first Olympics for all of us and the expectations were high, (Kim) might have been nervous."

Lee, too, admitted to battling nerves, saying he wasn't entirely happy with his performance despite his high scores.

"I didn't particularly feel great out there," he added. "I have to go back to the drawing board. There is a lot of time left until the final and this is only the beginning."

Also on Tuesday, Chang won both of her matches to reach the last 16.

She defeated Karoline Lusitania Tatafu of Tonga in the first round 6-0 (28-23, 27-15, 27-23), and then Lidiia Sichenikova of Ukraine 6-2 (28-27, 29-28, 26-28, 28-25) to advance.

These two victories have set up a meeting with North Korea's Kang Un-ju on Thursday. Kang knocked off Sarah Nikitin of Britain and Christine Bjerendal of Sweden in that order.

Chang said she expects the all-Korea showdown to attract plenty of attention, but she will stay focused on her own performance.

"We used to say hello to each other and have small talk when we met at competitions, though it's more difficult now with tighter security for North Korean athletes," Chang said. "This is the first time we'll face each other. I know what she's capable of, but I will only concentrate on my own game plan."

On the women's side, Ki Bo-bae has reached the round of 16, with Choi Mi-sun lined up for action Wednesday. (Yonhap)