Place tomatoes, wine, garlic, olives and rosemary in slow cooker and stir to combine. Sprinkle meat with 1 1/2 tsp. salt and pepper to taste. Place it on top of tomato mixture; spoon half of tomato mixture over meat to cover. Cover and cook on high until fork-tender, 5 to 6 hours.
Transfer brisket to a cutting board, tent with foil and let stand for 10 minutes. Skim fat from sauce; season with salt and pepper. Slice brisket across grain and transfer to a serving platter. Spoon some sauce over meat and sprinkle with parsley. Serve brisket with remaining sauce on side.