Cut pork into 1/2-inch slices. Sprinkle both sides of pork with salt and paprika.
Heat 10-inch nonstick skillet over medium-high heat. Cook pork in skillet 6 to 8 minutes, turning once, until no longer pink in center. Remove pork from skillet; keep warm. Wipe out skillet.
Heat same skillet over medium-high heat. Cook onion in skillet 1 minute, stirring frequently. Reduce heat to medium. Stir in sugar. Cook about 3 minutes longer, stirring frequently, until onion is soft and golden brown. Spoon over pork.