The Worksop player, ranked number 96 going into the tournament in Sweden, defeated world number nine Koki Niwa 3-0 as England sensationally sunk world top three team Japan 3-1.
It was the first time he had beaten a top-10 player.
The trio of Walker, Paul Drinkhall and Liam Pitchford also beat world number six team Chinese Taipei, as well as Belarus, Singapore and Belgium to win their group with a 100 per cent record and qualify for the quarter-finals.
But, with the backing of the home crowd, Sweden won three close matches to seal a 3-0 victory over England.
“It was pretty disappointing,” said Walker, who turned 23 this week.
“We’ve got a lot to be proud of as a team but it doesn’t matter if you don’t go away with a medal.
“Beating Japan, and me beating Niwa, was the high point of the tournament and we are all proud of that. It’s something good to take away, but we came here for a medal.”