Stalking Bettarun Fast swung four wide in the stretch to grab the lead under Aaron Gryder and went on to a three-quarters of a length win over Mystery Gal in the $100,000 Railbird (gr. III) for 3-year-old fillies at Hollywood Park Saturday.Coming off a win a win in the Santa Paula (gr. III) on a wet fast track at Santa Anita at odds of 31-1 April 1, Bettarun Fast was overlooked at odds of 5-1 in the six-horse Railbird. She completed the seven-furlong distance in 1:23 1/5.So Long Sonoma, the 2-1 favorite after winning the first two starts of her career, finished third for Jon Court in her stakes debut.Carrying top weight of 120 pounds, Bettarun Fast, a Florida-bred daughter of Kelly Kip-Split Decision (Dispersal), was positioned on the outside of the pacesetter El Mirage Queen, who sped through fractions of :21 4/5 and :44 1/5. Silly Little Mama gained a head's advantage in mid-stretch but was overwhelmed by Bettarun Fast, closing while four wide in the lane, and Mystery Gal, who made her move along the rail for Tyler Baze but could not match the winner late. So Long Sonoma closed willingly to take third."She's a nice, honest filly, and if she can just reserve her speed for the last part of it, she's very genuine," Gryder said of the winner.Vladimir Cerin, who missed the race because he was in the hospital for knee surgery, trains Bettarun Fast for owners Patricia and Stephen Fitzpatrick. Bettarun Fast, a $9,500 Ocala buy in August 2004, improved her record to 5-2-0 in nine starts with earnings of $228,505.Bettarun Fast paid $12.80, $6.40 and $3.80. Mystery Girl returned $7.60 and $3.80. So Long Sonoma was $3 to show. Silly Little Mama, Acceleration and El Mirage Queen followed.