Sokwakhana Zazini comes from the South African province of Eastern Cape . He started athletics at a young age and quickly specialized in hurdles. At the age of 15 he received a scholarship to TuksSport High School and therefore moved to the capital Pretoria . In 2016 he won several medals at national junior championships and improved his time by more than two seconds to 50.85 s. In March 2017 he ran a new U18 world record over the 400 meter hurdles in 48.84 seconds in a competition in Pretoria. He traveled to Nairobi as one of the favorites for the U18 World Championships . There he was able to live up to his role as a favorite and win the gold medal in 49.27 s. In addition, the following day he won a bronze medal with the Kenyan 4 x 400 meter mixed relay.
A year later he went to the U20 World Championships in Tampere in the older age group. There, too, he ran the fastest time in the final and won the gold medal. In April 2019 he started at the U20 African Championships in Ivory Coast. In the competition over 400 meters, he failed in the semifinals. In his favorite discipline, he won the gold medal in 50.35 s. In July he entered the Universiade in Naples as a student at the University of Pretoria , where he won two silver medals. On the one hand with the 4 x 400 meter relay and on the other hand over the 400 meter hurdles, which he finished in second place in a personal best of 48.73 s. The time meant a new U20 African record. In August he was disqualified when he started at the Africa Games .
Due to a bone sprain in his foot, on the recommendation of his coaching team, Zazini decided not to participate in the 2019 World Championships in Doha in order to prevent a possibly worse injury and instead to focus on the 2020 Olympic Games in Tokyo .