It is known that the thick tensor-ideal subcategories in a tensor triangulated cate-gory can be classified via its prime ideal spectrum.We use this to provide new proofs of two well-known classifications theorems:that of the thick tensor-closed triangulated subcategories of the stable category ofmodules over a finite group algebra, and that of the thick triangulated subcategoriesof the derived category of perfect complexes over a commutative Noetherian ring.