Gather your ingredients!
Whisk ketchup, garlic powder, vinegar, and brown sugar together in a bowl.
Whisk in 2 tbsp Worcestershire sauce.
Sprinkle half the salt & pepper over each side of trimmed brisket.
Pat to make salt & pepper "stick"
Place brisket in crock pot & pour mixture over the top.
Spread onion over the brisket.
Cover and cook on low for 6 hours.
Remove brisket from crock pot. Let sit for a couple minutes, then slice against the grain. Serve with juices spread over the top. Delicious!