Andreas Kramer, 25, used an unusual tactic for him in the semi-finals.
He started by laying far back in the field and then advanced during the second lap.
At the finish line, he rose from fifth place to finish first.
He won the heat narrowly ahead of Italian Simone Barontini and Frenchman Benjamin Robert.
The top three per semi-final plus two times advanced to Sunday's final.
In the last European Championship, in Berlin 2018, Kramer took silver.
He will now try to defend or improve that in Munich.
Kramer has a personal best of 1.44.47 from 2020. It is also a Swedish record.