Royal Son showed an affinity for Polytrack when posting a convincing win in the Battaglia Memorial (Turfway Park/Coady Photography)

El Camino Real Derby (G3) winner Metaboss (Street Boss) will take on John Battaglia Memorial romper Royal Son (Tiznow) in Saturday's $550,000 Spiral Stakes (G3) at Turfway Park. The 1 1/8-mile Polytrack event drew a capacity field of 12 and serves as the final Kentucky Derby (G1) qualifying race on synthetic, offering points on a sliding scale of 50-20-10-5 to the top four finishers.

Royal Son is listed as the 7-2 morning line favorite and will break from the innermost post with a returning Rodney Prescott. The colt took a great leap forward in the final local prep, the Battaglia Memorial, becoming yet another Derby hopeful in Todd Pletcher's quiver. Adding blinkers off a non-effort in the January 31 Sam F. Davis (G3) at Tampa Bay Downs, the WinStar Farm homebred posted a wire-to-wire tour de force. His 5 1/4-length conquest was good for a 103 BRIS Speed rating, best in the Spiral field.

Metaboss has blossomed since stretching out to two turns. Best of the rest behind Bolo (Temple City), the eventual Eddie Logan winner and San Felipe (G2) third, in a 1 1/16-mile turf maiden, he has since won two straight at the Spiral distance. The Jeff Bonde trainee uncorked a visually impressive turn of foot to break his maiden on the Santa Anita turf January 4, and did the same to capture the February 14 El Camino Real Derby by 2 1/2 lengths on the Golden Gate Fields Tapeta.

Installed as the 4-1 second choice on oddsmaker Mike Battaglia's morning line, Metaboss will break from post 11 with Hall of Famer Alex Solis back aboard.

Metaboss brings a two-race win streak and strong late kick to the Spiral (Shane Micheli/Vassar Photography)

"We will look (Imperia) over good, but we are just not happy with him," the trainer told Daily Racing Form.

Conquest Typhoon was only third in the El Camino Real Derby, but the Mark Casse pupil had a tough task while arguing the pace off a 2 1/2-month layoff. His best performances have come from off the pace -- wins in the Summer S. (Can-G2) at Woodbine and Cecil B. DeMille (G3) at Del Mar. Yet those came on turf, and Conquest Typhoon is zero-for-3 on synthetic, including a second to eventual Risen Star and Lecomte (G3) hero International Star (Fusaichi Pegasus) in last fall's Grey S. (Can-G3). He could answer that stat under a more typically patient ride by Hall of Famer Mike Smith.

Fair Grounds invader Another Lemon Drop (Lemon Drop Kid) finished fourth to International Star (Fusaichi Pegasus) in January's Lecomte (G3) before a runner-up effort as the even-money favorite in the February 28 Black Gold at about 7 1/2 furlongs on turf. The Philip Bauer-trained colt will by trying synthetic for the first time Saturday but figures to benefit from the added ground, having broken his maiden going 1 1/8 miles on the Keeneland turf in October. He's been tabbed at 6-1.