Gun Salute got up by a whisker in Saturday's $250,000 American Derby (gr. IIT) on Arlington Park's turf course, handing the even-money favorite Purim his first loss in four starts.Ridden by Cornelio Velasquez, Gun Salute chased Purim all the way down the lane and reached the wire and the lead instantaneously. Gun Salute got the nod by an official nose for his first graded stakes win. The Bill Mott-trained son of Military completed the 1 3/16-mile test for 3-year-olds in 1:55 1/5 on good going.The Arlington Classic (gr. IIIT) winner Purim wasn't challenged in his three previous races, two of them on the turf, but had not raced farther than 1 1/16 miles. After Purim, who was ridden by Mark Guidry, disposed of the pacesetter General Jumbo coming off the final turn, he opened up by a couple of lengths in the stretch but could not withstand the relentless pressure from Gun Salute in the final furlong."You win some, you lose some," said Purim's trainer Tom Proctor. "That one was close. If you won them all, no one would want to race with you. This colt has done everything we could have asked of him. He won his first three starts. He ran his heart out and just got beat."Exceptional Ride, 3 1/2 lengths behind, finished third with James Graham aboard.General Jumbo broke alertly from his inside post and, after engaging with Purim for the early lead, quickly pulled away to lead by about seven lengths while clicking fractions of :23, :47 and 1:11 2/5. Purim waited patiently in second with Gun Salute glued to him in third while racing three wide.Brant Laue bred and owns Gun Salute, who was coming off a third-place finish in the Jefferson Cup (gr. IIIT) at Churchill Downs June 18. The bay won his prior start two months earlier, Keeneland's Forerunner April 21, by 2 1/2 lengths. "This is my first homebred runner, ever," Laue said. "To have him prevail at a great track like Arlington on a big day like this is special. There are a lot of opportunities for good 3-year-old turf horses and this was certainly a prime target for us."The Kentucky-bred, produced by the Roberto mare, Hail Roberta, won for the fourth time in eight career starts with earnings of $298,344.Ken McCarthy, assistant to Mott, indicated the $400,000 Secretariat Stakes (gr. I) at Arlington on Aug. 13 could be the next start for the bay colt."Mr. Laue and Mr. Mott will talk that over, but I am certain it is in the forefront of their considerations right now," McCarthy said. "He's been an awfully nice horse for us. All last year, Bill always thought a lot of him so it was great to see him get a graded stakes win today."The third choice in a field of eight, Gun Salute paid $9.40, $3.40 and $2.80. Purim returned $2.60 and $2.20. Exceptional Ride's show was $3.80. Cosmic Kris finished fourth, followed by General Jumbo, Merger, Gold Minister, and Earths Vain Shadow.(Chart, Equibase)