FC Sion's 3-0 win at St. Gallen means that the Bernese Oberland club can no longer be caught at the top of the Swiss League in the remaining rounds.
FC Thun have been the revelation of the season in the Swiss Super League, dominating the championship since October and managing to leave behind traditional forces such as FC Basel and BSC Young Boys despite a considerably smaller budget.
The team's story, as recently promoted and contending for the title, has few equals in European football. Similar examples in the last 50 years are the triumph of Nottingham Forest in 1978 or the success of FC Kaiserslautern in the Bundesliga two decades later.
Thun has had a more than modest history from a trophy perspective. They first reached the first division in 1954, but were quickly relegated, and in the following decades they were confined to the lower leagues. The return to the elite in 2001 marked the beginning of a more stable period.
Their best finish before the current season was second place in 2005, behind Basel. A year later, the club managed to qualify for the UEFA Champions League groups, where they beat Sparta Prague and gave Arsenal serious problems, with the Londoners having to battle hard for success in both matches against the Swiss contenders.
Current manager Mauro Lustrinelli was part of the squad in that European campaign and has now led the squad to their greatest ever performance and return to the Champions League 20 years after that participation.
Despite reaching the Swiss Cup final twice before, Thun had never managed to win a major trophy until this season, when the success story reached its peak.