Snap tough ends off of asparagus*. Spread asparagus on a baking sheet coated with foil. Drizzle with oil and sprinkle with salt, pepper, and garlic powder; toss to coat.
Arrange asparagus on grill grates in the opposite direction Cook over medium heat for 5-10 (depending on thickness) minutes turning every minute to avoid charring. Spritz with fresh lemon juice. Serve immediately.
*To trim asparagus, hold each end of the spear and gently bend it until it naturally snaps — usually about 2/3 of the way down. Discard the bottom, woody part of the spear (or save for vegetable stock).