Heat oven to 400°F. Line large baking sheet with foil or parchment paper. Coat with no-stick cooking spray.
Combine ground beef, potato flakes, eggs, milk, onion, garlic, chili powder, salt and pepper in large bowl. Form meatballs about 1 1/2 inches in diameter, using small cookie scoop or 2 tablespoons meat mixture. Place on prepared baking sheet.
Bake 20 to 30 minutes or until golden brown. Drain on paper towel lined plate, if necessary.
Combine ketchup, brown sugar, garlic, onion, vinegar and Worcestershire sauce in small saucepan. Heat over medium-high heat until comes to a boil. Simmer 5 minutes, stirring occasionally. Toss cooked meatballs in glaze.