The 25-year-old was looking to put in a strong performance having lost to his younger brother Jonny in Hamburg at the end of July and held onto his lead after edging clear during the bike stage.
His time of 1:43:13 helped him finish 14 seconds ahead of Spain's Javier Gomez with Jonny in third a further 23 seconds back and he now leads his younger brother by 65 points in the standings.
Victory in Sweden was Alistair's 15th World Triathlon Series win of his career and sets up an exciting finale at the Grand Final in London on September 15.
A win for either Brownlee in London will see them take the title and after a year of injuries, Alistair insists it would be a great way to end a difficult season with victory in London.
"It has been a year of injuries and disaster and not really wanting to turn up, but it is all about winning when I am not having a good day, and finding ways to do that," he said.
"I was going better than I thought. I've had a good last two weeks and now I have another three weeks before London so I can be pretty fit, but Javier is pretty fit as well so it should be a great race.
"I will try my best and that is all you can ask."