Belgian Remco Evenepoel was superior, but behind him Söderqvist was in the fight for silver and bronze until the very end.
Olympic gold medallist Evenepoel took his fourth world championship gold in the time trial, finishing just over 57 seconds ahead of Italy's Filippo Ganna, who finished second. Frenchman Paul Seixas took bronze, 1.13 seconds behind the winner.
Söderqvist came fifth and was around 13 seconds away from bronze.
Last year, the 23-year-old Swede won gold in the time trial at the U23 World Championships.
