In 2017, Dalaloyan had a career breakthrough where he became the 2017 Russian National all-around champion. He then competed in his first major senior event at the 2017 European Championships where he won the all-around silver medal behind Ukraine's Oleg Vernyayev. He qualified in the vault finals where he won the gold medal ahead of Marian Drăgulescu. On August 23–27, Dalaloyan competed at the Russian Cup in Ekaterinburg, he won gold in team, in the all-around after bombing in pommel horse; he slipped into 4th place behind Nikita Ignatyev. In the apparatus finals, Dalaloyan won gold in vault (tied with Nikita Nagornyy) and 2 silver medals on Parallel Bars and Floor Exercise.