Place each chicken breast between two pieces of plastic wrap and pound thinly (about 1/4 inch thick) using a meat mallet.
Season both sides of each flattened breast with salt and pepper.
Set up a dredging station: flour in one shallow dish, beaten eggs with milk in another, and breadcrumbs mixed with garlic powder and paprika in a third.
Coat each chicken cutlet first in flour, shaking off excess.
Dip the floured cutlet into the egg mixture, letting excess drip off.
Press the cutlet into the breadcrumbs until evenly coated; gently shake off loose crumbs.
Heat oil in a large skillet over medium-high heat until shimmering but not smoking (about 350°F / 175°C).
Carefully lay cutlets into the oil without crowding; fry 3–4 minutes per side until deep golden brown.
Transfer cooked schnitzels to a wire rack or paper towel-lined plate to drain briefly.
Finish with a squeeze of lemon, sprinkle with parsley, and serve immediately while crisp.