Keys to the Heart, sent off at 17-1 in a four-horse field with Jose Valdivia Jr. in the saddle, kicked loose in the stretch and held off Rhiana near the wire to tally a half-length upset in Friday night's $103,292 Hawthorne Handicap (gr. III) for fillies and mares at Hollywood Park.The 4-year-old daughter of Wild Again, trained by Beau Greely, went the 1 1/16-mile distance in 1:42 4/5.Se Me Acabo was third by a head but was disqualified and placed last behind 1-2 favorite Alexine, who took up sharply off the heels of Se Me Acabo in deep stretch.Keys to the Heart rated behind pacesetting Se Me Acabo and Felipe Martinez through :23 1/5, :48 1/5 and 1:12 fractions, collaring the leader on the turn for home. After opening a two-length lead in the stretch, she was able to turn back the challenge of Rhiana and jockey David Flores while urged home strongly by Valdivia.The victory, worth $63,240 to Kentucky breeder/owner Thomas Nichols, came in Keys to the Heart's graded stakes debut. She was coming off an eighth-pace showing in the ungraded Miss America at Bay Meadows on April 5. Her only other victory in 15 starts came in a maiden special weight event at Churchill Downs in November 2001. She increased her career earnings to $145,640.Keys to the Heart paid $37 and $12.60. Rhiana returned $6. There was no show wagering. The $2 exacta was worth $115.20.