Milanov broke his own Belgian record again in Kessel-Lo on 25 April 2015, throwing 66.43 m and meeting the qualification standard for the 2015 World Championships in Beijing. In July 2015 he won gold with 64.15 m at the World University Games in Gwangju, South Korea. He unexpectedly scored his first Diamond League victory two weeks later at the London Grand Prix; in rainy conditions, he threw 65.14 m to defeat a field that included Diamond Race leader Piotr Małachowski of Poland. In August 2015 he broke again his Belgian record and met the qualification standard for the 2016 Olympic Games. On 29 August 2015 at the World Championships in Beijing, where he took silver, Milanov, improved his national record to 66.90 m.