Place the peaches, apple juice, garlic, onion, vinegar, lemon juice, and chili powder in a saucepan over medium heat.
4 ripe peaches, 1 cup fresh apple juice, 2 garlic cloves, ½ onion, ⅓ cup apple cider vinegar, 1 tbsp. fresh lemon juice, 2 tbsp. chili powder, Sea salt and freshly ground black pepper
Bring the sauce to a boil, stirring occasionally. Lower the heat and let simmer for 10 to 15 minutes.
Let the sauce cool down a bit and puree using a food processor or immersion blender.
Divide the peach BBQ sauce evenly into two separate portions. Use one portion to rub the pork, making sure it is covered on all sides. Cover and marinate for up to 2 hours in the refrigerator.
1 lb. pork tenderloin
Keep the other half of the BBQ sauce in a separate container in the refrigerator.
Preheat a grill to medium heat.
Place the pork on the grill and cook, covered, for about 20 to 25 minutes, turning the pork every 4 minutes or so.
Brush the pork with a generous amount of the reserved BBQ sauce and grill for another 5 minutes.
Let the pork rest for 4 to 5 minutes before serving it with the remaining BBQ sauce.