[12][13] An participated in his third junior world championships in Fort Lauderdale, where he moved up a weight class to the half-lightweight category.
He was anticipated to becoming the tournament winner as the defending champion, and looked to be on form, defeating Colombia's Andres Chapparo in his first fight by ippon with kata-gatame.
– An Ba-ul after winning the Teams title with Korea An had a smooth start in his first official senior tournament at the Grand Prix in Jeju, where he defeated Mongolia's Batsuuri Adiya for ippon with an unorthodox osaekomi-waza.
[17] In his second fight against Spain's Sugoi Uriarte, he won by yuko with a seoi nage to kosoto gake combination.
[18] An met Russia's Anzaur Ardanov in the quarter-final, and scored first with a waza-ari using a kosoto gari to seoi nage combination.
He scored an ippon with a drop sode tsurikomi goshi[23] in less than fifty seconds, making the fight his shortest win.
An then faced Russia's Alim Gadanov in a tight fight, winning narrowly by yuko with uchi mata.
Ebinuma threw An for waza-ari with yoko guruma, and then pinned him with tate shiho gatame for awasete ippon, ending An's chances of gold.
In the bronze medal contest, he faced another tough opponent in two-time world silver medalist Mikhail Pulyaev.
[28] An then had a difficult match up against Japan's Kengo Takaichi, where he was thrown for waza-ari in the opening minute with yoko guruma, and then was nearly pinned with tate shiho gatame, similar to Ebinuma's score against him in Tokyo.
He faced Tajikistan's Umed Abdurakhimov in his first fight, and scored a yuko in the opening seconds with a drop seoi nage.
The bout had a fair share of newaza, however remained scoreless until An's drop sode-tsurikomi-goshi that landed Ma on his side, earning the former a yuko.
There was an array of seoi nage attacks from both An and Takajo, and the latter was the one to score with yuko, leaving An to settle for silver, his first continental medal.
[38] In the semi-final, An faced Kyrgyzstan's Bektur Ryzmambetov, and scored two waza-aris for awasete ippon closing into the final.
[39] An faced France's Alexandre Mariac in the gold medal contest, and scored a yuko in just 15 seconds with one of his signature skills drop sode-tsurikomi-goshi.
With a minute and half left, An threw Mariac for ippon with another signature skill single lapel morote seoi nage to win the gold medal.
He again scored waza-ari with a drop single sleeve morote seoi nage for awasete ippon with 30 seconds to spare.
Khan-Magomedov was penalised thrice by the fourth minute, and had a glimmer of a score when he moved play to newaza and attempted an okuri eri jime before it was stopped by the referee as An escaped.
Korea won 4–1 again, with world champion Gwak supposedly losing on purpose to save energy for the final.
The final featured reigning and former world champions across five weight divisions, namely An and Gwak for Korea, and Ebinuma, Riki Nakaya, Takanori Nagase and Ryunosuke Haga for Japan.
An Chang-rim managed to get the Koreans back by defeating Nakaya with a drop seoi nage effort, initially scoring waza-ari, then re-scored to ippon.
However, An brought the fight to the ground and secured a pin using kata gatame to koshi jime, earning a submission for ippon.
He contested against Kazhakstan's Gabit Yessimbetov in the Round of 16, with both of them earning shidos for refusing to take a grip in the opening minute.
[68] An regained form in the final, defeating Slovenia's Andraz Jereb by ippon with a rare uchi-mata-sukashi, earning him a bronze medal.
An entered his second Düsseldorf Grand Prix, traveling to the tournament with a top class Korean team.
[83] He again fought Pollack in the quarter-final, but showed his superiority when he landed the latter on his back for ippon with his strong seoi nage in less than 20 seconds.
He continued his ippon streak in the third round with another waza-ari with seoi nage, and then landed his opponent from France, Kilian LeBlouch, with sode-tsurikomi-goshi flat on his back.
Both of them were penalised with shido for defensive posture in the beginning of the bout, and An sealed his place in the semi-finals with a seoi nage for waza-ari.
His fight against long-time rival Masashi Ebinuma of Japan was reminiscent of the Japanese bout at the 2012 Olympics against An's countryman and coaching staff Cho Jun-ho.
Ebinuma again attacked with a drop ippon seoi nage, only to get countered by An with tani otoshi for yuko, effectively ending the bout with a win to An.