In a large mixing bowl, combine the blueberries, white sugar, and lemon juice; let sit for at least 15 minutes before continuing recipe.
Preheat oven to 350 degrees.
Prepare cake mix according to box.
Melt butter in 13x9-inch pan in oven. Sprinkle brown sugar evenly over melted butter; give blueberries a good stir and then pour them over butter and brown sugar mix.
Pour cake batter on top and bake for 45 to 60 minutes; run a knife around the edges of the cake.
Place serving dish over top of pan and flip cake onto it. Leave pan over dish for a few minutes before serving. (This allows the glaze to drip into cake instead of running down its sides.)
