In a mixing bowl, whisk together the olive oil, red wine vinegar, garlic, Worcestershire sauce, smoked paprika, salt, black pepper, onion powder, and rosemary.

Place the tri tip in a resealable bag or a shallow dish and pour the marinade over it. Seal the bag or cover the dish, then refrigerate for at least 30 minutes or up to 4 hours.

Preheat your grill to medium-high heat, around 400°F.

Take the tri tip out of the marinade and let any excess drip off.

Place the tri tip on the grill and sear for about 5-7 minutes on each side.

Using a meat thermometer, check for doneness. Aim for 130-135°F for medium-rare.

Once done, remove the tri tip from the grill and let it rest for 10 minutes.

Slice the tri tip against the grain into thin slices.