To test Ghostzapper's stamina, Frankel entered him in the Philip H. Iselin Breeders' Cup Handicap at Monmouth Park Racetrack on August 21 over a distance of miles. Over a muddy track, Ghostzapper won the race by 10 lengths in 1:47.66. He earned an astonishing 128 Beyer Speed rating, the highest ever assigned by the "Daily Racing Form" since they started publishing the numbers in 1992. The "Form" stated categorically, "There can be no argument that Ghostzapper is the fastest horse in the country." (Before the numbers were published by the DRF, a few higher numbers were assigned by handicapper Andrew Beyer. Groovy, 1987 American Champion Sprint Horse, was the last horse to break the 130 Beyer Speed Figure, earning 133 and 132 in back-to-back 6-furlong races in 1987.)