Sun Jiajun is a Chinese sprint breast and fly specialist. He has won World Championship medals and is a one-time Aisan record holder in the 50 breast.
2017 Chinese Summer Nationals (Ganzhou, China)
Sun nearly won a national title with a 2:13.72 200 breast, just .08 back of Zhang Rui Xuan. Sun was just 16 years old.
2018 Youth Olympics (Buenos Ares, Argentina)
Sun won the 100 breast in a quick 1:00.59, well ahead of Dennis Petrashov’s 1:01.34. Jiajun was out quick in 27.72, not far off his 50 breast PB. on the 400 medley relay, Sun split a 1:00.12 on breast to out China in 2nd, a spot they maintained to the finish. Now seemingly red hot, Sun cruised through the 50 breast prelims with a 27.91 and semis with a 28.05. In the finals, he faced off against Michael Houlie who went 27.33 to lead semis. Houlie was off in the final but he still topped Sun 27.51 to 27.85. In the very next event, Sun reaped another medal. Sun split a quick 1:00.22 to help China win the miced 400 meldey relay.
2019 Chinese Youth Games
Sun broke a big barrier in the 100 breast with a swift 59.92. It was Sun’s first time under 1:00 in the 100 breast.
2018 Asian Games (Jakarta, Indonesia)
Sun was one of 5 men under the previous 50-breast Asian Games Record in prelims with a 27.48 to qualify 4th. The leader of the bunch was Sun’s compatriot Yan Zibei. Sun ended up 4th in the final with a 27.65.
2020 Summer Test Competition (Shandong Province, China)
Sun and several other Chinese national team members were in the water competing against one another in a closed competition before heading to a 3-week training camp. In the 100 fly, then a bit of an off event for Sun, he threw down a 52.00, an unofficial PB. In the 100 breast, he edged Yan Zibei with a 59.53, another unofficial PB.
2020 Chinese Long Course Invitational (Shijiazhuang City, China)
Sun neared his best 100 fly time with a 52.51.
2021 Chinese Swimming Meet (Shaoqing, China)
Sun had a big 100 fly, dipping into the 51s for the first time ever with a 51.85
2020(1) Chinese Olympic Trials (Qingdao, China)
In the 100 breast, Sun ended up 2nd in 1:00.24. Unfortunately, that time was not under the “A” cut he needed. Sun topped the 100 fly in 51.97, a mere .01 off the “A” cut.
2021 Chinese Summer Nationals
After a disappointing Olympic Trials, Sun had a 2nd chance at Summer Nationals. There he just eeked under the QT with a PB of 51.93 to become China’s newest Olympic team qualifier.
2020(1) Olympic Games (Tokyo, Japan)
Sun made it out of prelims in the 100 fly by just .08 seconds. He posted a PB of 51.74, good for 16th. In semis, he improved to 13th, landing him out of the final, despite adding slightly to a 51.82. Sun also was on the Chinese 400 medley relay and split 51.81 to help China qualify for the final in 4th. A disqualification in the final meant a medal was out of the question for Sun.
2021 Chinese National Games (Shaanxi, China)
Sun took silver in the 100 breast with a mark of 59.83.
2021 FINA SC World Championships (Abu Dhabi, UAE)
Sun just swam fly at his first SC Worlds. He had solid succes in the 100 fly with a 50.92 for 20th but the big highlight came in the 50 fly. Sun broke his first national record with a 22.64 for 8th. In semis, he lowered it a further .01 seconds to 22.63 and finished in 11th.
2022 FINA World Championships (Budapest, Hungary)
Sun just swam the 50 fly and placed 32nd in 23.83.
2022 Chinese SC Swimming Championships (Beijing, China)
Sun nearly won the 100 breast but end up 2nd to Qin Haiyang after turning first at the 50 and 75 mark. Sun put up a 56.43, just .12 back of Qin, who set the NR with his swim. Sun won the 200 breast in 2:06.06.
2022 FINA SC World Championships (Melbourne, Australia)
Sun missed out on a 2nd swim in the 100 breast with a 57.92 for 17th. The time was well off his season and lifetime best of 56.43 which could have placed as high as 5th in the final.
2023 Chinese Spring Championships (Qingdao, China)
Behind Qin Haiyang’s big 58.66 in the 100 breast, Sun had a PB of his own with a 59.00 to then rank as the #3 100 breast swimmer in the world for the 2022-23 season. Sun’s time cleared the World Aquatics “A” cut. In the 100 fly, Sun neared his PB and came up with another 2nd-place finish courtesy of his 51.87. The time was another World Aquatics “A” cut. Sun missed a 3rd qualification as he settled for 3rd with a 23.43 in the 50 fly. He came back and took another silver in the 50 breast with a speedy 26.80 PB, just .03 behind Qin.
2023 Chinese National Championships (Hangzhou, China)
2023 Nationals represented the 2nd of 2 opportunities to qualify for 2023 Worlds after Spring Championships. She sipped under 59 seconds for the first time in 58.99 for 3rd behind Qin’s historic 57.93 and Yan Zibei’s 58.79. Sun tied for the win in the 50 fly with a new PB of 23.41 and settled for silver in the 100 fly with a 51.74, just .01 seconds back of gold and equal ing his PB. It was his domestic rival Wang Changhao who tied and beat Sun in the fly events.
Sun’s big swim came in the 50 breast where he threw down a 26.61, a new Chinese and Asian Record While Sun improved in both 50 fly and 100 breast, he was not selected for Worlds in either. Sun still qualified in the 100 fly and 50 breast. He also qualified for Asian Games.
2023 World Aquatics Championships (Fukuoka, Japan)
In the 50 breast, Sun had machine-esque consistency through all three rounds of the 50 breast. His times from all three rounds were separated by a matter of a couple of inches. Sun qualified 3rd in prelims with a 26.76. In semis, he remained 3rd with a 26.78. In the final, Sun secured bronze with a 26.79, helping China to a 1-3 punch with Qin. Qin had broken Sun’s continental record in prelims. He was off in the 100 fly with a 52.16 for 25th but still got to swim on the prelims 400 medley relay and split 52.35. The finals squad took home sliver.