In a baking dish or large bowl, combine the soy sauce and Worcestershire sauce.

Add the tenderloin and turn to coat all sides. Marinate for a minimum of 15 minutes, or up to a couple hours if desired. Season all sides with garlic and onion powders, and salt and pepper.

Preheat grill to 400 degrees. Grill pork tenderloin for about 5-7 minutes per side (turning 4 times) totaling around 25 minutes, or until desired temperature is reached. 155 degrees will give you medium-medium/well. Use a meat thermometer for best results.

Allow tenderloin to rest for 5-10 minutes before slicing.