Katerbug made the winning move by exploding from a tight group of 3-year-old fillies in the upper stretch en route to her first stakes victory Saturday in the $50,000 Audubon Oaks at Ellis Park in Henderson, Ky. Sent away a lukewarm favorite in a field of 12, Katerbug returned $7.60 after finishing a length clear of Bel Air Beauty in the 1 1/16-mile turf race. Si Si Mon Amie, who set most of the pace, finished third. G. Watts Humphrey Jr. is the breeder and owner of Katerbug, a Pulpit filly who had finished second in a Churchill Downs allowance last month in her only start this year. Katerbug is based at Churchill Downs with trainer Rusty Arnold and assistant Jack Bohannan.