Lengdén spent four years and won two NCAA Division titles at Nova Southeastern University in Fort Lauderdale before he returned to Europe and turned professional in 2015.

He finished third on the 2016 Nordic Golf League ranking to become a Challenge Tour rookie in 2017.

[1] Lengdén made it to the final qualifying stage at the European Tour Qualifying School in 2016 but failed by one stroke to earn a European Tour card.

[2][3] He made a handful of starts on the 2017 European Tour and finished tied for fifth at the D+D Real Czech Masters.

His run of form continued when, the next week, he was joint runner-up in the Irish Challenge, after which he rose to 186 on the Official World Golf Ranking.