in 2017, unterbuchner reached the last 48 of the world masters. he qualified for the 2018 bdo world darts championship as one of the playoff qualifiers, he played david cameron in the preliminary round, winning 3–2. unterbuchner became the first german player to reach a semi-final at a world championship, as well as the first to win a last 16 match at a world championship, when he caused an upset by beating #3 seed jamie hughes 3-2 in the first round, #14 seed martin phillips 4-2 in the second round and #11 seed richard veenstra 5-4 in the quarter final. he played #2 seed and bdo nr. 1 mark mcgeeney in the semi-finals where he lost 6-4.