It was North Korea's third weightlifting gold medal in Incheon.
Asked whether she knew she would win the gold, the 23-year-old said that she knew she had "the guts to win."
The lifter had failed to complete her third snatch attempt within the set time limit but more than redeemed herself with a strong clean and jerk.
Ri is not an unfamiliar face on the international stage, as she grabbed a silver at the Asian Weightlifting Championship as well as a gold at the Asian Cup and Interclub Senior Weightlifting Championship, both held last year.
Kim Su-ryon, another North Korean weightlifter who failed in her attempt to claim a medal and ended in fifth place the previous day, joined other delegates of the isolated country to root for her weightlifting compatriot. Sheikh Ahmad Al Fahad Al Sabah, president of the Olympic Council of Asia, also attended the competition.