Möregårdh started Friday's round of 16 convincingly and took the first set 11-6.
The second set was a more even affair, but Truls Möregårdh showed his experience and won 12-10.
The Swede then had two match points in the third set, but Shunsuke Togami came back, defended well and narrowed the match to 13-11.
In the fourth set, the Japanese player was sharper at the start and led by two points, but Möregårdh stepped up, won 11-5 and is ready for Saturday's quarterfinals. Darko Jorgić from Slovenia awaits there.
Anton Källberg will also play in the quarterfinals on Saturday. He will face French star Alexis Lebrun.
