亞歷山大•烏爾森巴赫

Ursenbacher started playing snooker in 2008. He has won a host of junior titles in his native Switzerland and has won the national championship twice, due in large part to his stays at Snooker Academies in Sheffield and Gloucester and individual training by former World Championship semi-finalist Ian McCulloch.

He turned professional by coming through the 2013 Q School. After an early defeat in Event One, he played superbly throughout Event Two, losing just one frame in four matches and scoring a top break of 140. He beat nine-time Ladies' World Champion Reanne Evans 4–1, then in the final round he saw off experienced former pro Paul Wykes 4–0.

Ursenbacher experienced a tough start to his debut season as a professional, losing his first seven matches. His first win came in November at the minor-ranking Kay Suzanne Memorial Cup against former world champion Ken Doherty, and he was close to following it with another defeat of a world champion in the form of Peter Ebdon in the next round, ultimately losing 4–3. He failed to win another match until the season-ending World Championship, where he came back from 6–2 down to win 10–7 against David Morris. He lost in the next round 10–5 to Thepchaiya Un-Nooh.

Ursenbacher qualified for the first ranking event of the 2014–15 season, the 2014 Wuxi Classic, by beating Kyren Wilson 5–4, but had to withdraw from the tournament due to being unable to enter China because of a visa problem. He defeated Martin O'Donnell 5–4 in the first round of qualifying for the Australian Goldfields Open, before losing 5–2 to Lyu Haotian and then lost a further 14 consecutive matches to be relegated from the tour as the world number 119. Ursenbacher won five games in the first event of the 2015 Q School to reach the final round where he lost 4–1 to Daniel Wells. In the second event he was eliminated in the last 32 by Joe Roberts.

Out of the three European Tour events Ursenbacher entered in the 2015–16 season, he reached the first round of the Ruhr Open, where he lost 4–3 to Rod Lawler. He was knocked out in the opening round of the first 2016 Q School event, but in the second event he won five matches to stand just a game away from rejoining the professional tour. Ursenbacher lost it 4–2 against Alex Borg.

In March 2017 he won the EBSA European Under-21 Snooker Championship in Nicosia and with it re-qualified for the Main Tour. The victory also allowed Ursenbacher to get an invitation to the World Championship qualifying rounds; he defeated Robert Milkins 10–6 and Scott Donaldson 10–9 to reach the final round (he was the only amateur present at this stage), where he lost 10–4 to Yan Bingtao.

Ursenbacher recorded his best result to date by reaching the semi-finals of the 2017 English Open, defeating former world champion Shaun Murphy along the way; he lost 3–6 to Kyren Wilson. Ursenbacher's form declined after that, however, and he failed to win a single match for the rest of the season, aside from non-ranking event Shoot Out. The next season was hardly an improvement, although Ursenbacher caused a major upset at the 2019 Welsh Open by knocking out tournament favourite Ronnie O'Sullivan in the third round; he lost his next match to Zhao Xintong. After losing his first round qualifying match for the World Championship 4–10 to Jordan Brown, Ursenbacher was left 69th in the season-end rankings, confirming his relegation.

Ursenbacher came through the third event of the 2019 Q School by winning six matches to earn another two-year card on the World Snooker Tour for the 2019–20 and 2020–21 seasons.

In July 2020, he became the first Swiss player to qualify for the main draw World Championships. Ursenbacher was beaten in the first round 10–2 by 15th seed Barry Hawkins.