In a small bowl, combine lemon juice, lemon zest, garlic powder, salt, and black pepper.
Pat chicken breasts dry and rub the lemon pepper mixture all over both sides of each piece.
Heat olive oil in a large skillet over medium-high heat until shimmering.
Add chicken breasts to the pan and cook for 6-7 minutes without moving them, until golden brown on the bottom.
Flip the chicken and cook for another 5-6 minutes until the internal temperature reaches 165°F.
Add butter to the pan and let it melt, spooning it over the chicken.
Remove from heat, let rest for 5 minutes, garnish with fresh parsley, and serve.