For the sweet tomato soy sauce: Stir together the ketchup, soy sauce, Worcestershire and brown sugar in a small bowl and refrigerate until ready to use.
For the pork cutlets: Put the flour in a wide, shallow bowl; the eggs in another; and the panko in a third.
Poke the pork with a fork a few times to tenderize it, then sprinkle the pork with salt and pepper. Heat about 1/4 inch oil in a large skillet over medium-high heat until shimmering. Meanwhile, working in batches, dredge the pork in flour. Shake off the excess and dip in the eggs, letting the excess drip off before coating in the panko. Fry in the oil, turning once, until golden brown on both sides and just cooked through, about 2 minutes per side. Transfer to a paper towel-lined plate to drain. Repeat with the remaining pork.
Serve the fried pork cutlets with the sweet tomato soy sauce.