Nikita Artemenko, who is competing at the championships in Slovenia under a neutral flag, is ranked 76th in the world but gave Anton Källberg a scare.
The Swede, ranked 29th in the world, won the first two sets, but Artemenko levelled the match by winning the next two.
The match turned into a thriller, but Källberg came out on top in the seventh and deciding set, 11–8.
World number four Truls Möregårdh is also through to the second round after a convincing 4–0 win over Dutchman Ivan Kahn.
Kristian Karlsson and Elias Ranefur also won their first-round matches.