Brewster, a silver medallist 12 months ago, gave up three points in the opening end of his round-robin match with Danish rival Stjerne and was always struggling, eventually going down 9-7.
"We just got off to a bad start and never really got it back to be honest," he said.
"We made a lot of good shots, but we just didn't get the breaks.
"The fifth was a turning point and the three at the first end was just a soft three."
In contrast, Stjerne was delighted with his performance after a mixed opening day in Basel.
"That's one for the books," he said. "We came on strong and played a really good first five ends. We felt we had a chance from the start and we took it, and it paid off.
"They were silver medallists last year, so that's a big win to put in. We feel like we can start building momentum now."
1 Canada 3-0
1 Sweden 3-0
3 China 2-1
3 Denmark 2-1
3 France 2-1
3 Scotland 2-1
7 Czech Republic 1-2
7 Germany 1-2
7 New Zealand 1-2
7 Norway 1-2
11 Switzerland 0-3
11 USA 0-3