Cut open the avocado, remove the pit, then scoop out the flesh and place in a medium bowl. Mash the avocado with a fork, spoon, or potato smasher until it's broken down into small chunks.
Dice the tomato, red onion and serrano pepper, then mix in with the avocado.
Add the mayonnaise, Worcestershire sauce, lime juice, and garlic powder and combine until thoroughly mixed.
Add a pinch of salt and a dash of pepper and mix well, adjusting the seasoning to taste.
Tear the leaves of a handful of cilantro and sprinkle into the guacamole, leaving a few leaves on top as garnish. Serve with tortilla chips and enjoy!