Michael Jepsen Jensen became the home team's top rider with three heat wins and a total of 13 scored points.
Maksym Drabik and Gleb Tjugunov also played a major part in the clear victory, ensuring the home team finished the evening with a five in the last heat.
The Lions had the evening's best point scorer in Bartosz Zmarzlik, but the Pole's fine performance – four heat wins and a second place – could not help the team.
The return match will be held in Gislaved on September 9.
The second semi-final match between Indianerna and Västervik was postponed due to poor weather forecasts.
The first semi-final in that meeting will be held on September 8 and the return match the day after.
