04/23/2004 12:00AM

American Post starts season


American Post should deliver the goods at Longchamp on Sunday as he continues his classic preparations in the Group 3 Prix de Fontainebleu.

A winner of two Group 1 races last year at 2, American Post began this season with a handy score in the listed Prix Omnium II at Saint-Cloud on March 31. Trainer Criquette Head-Maarek is using the one-mile Fontainebleau as a springboard to the May 16 Poule d'Esaai des Poulains, or French 2000 Guineas, but it will also serve as a prep for the Epsom Derby on June 5.

Euopean juvenile champ Bago had been expected to challenge American Post, but a minor setback last week is forcing trainer Jonathan Pease to send Bago directly to the French 2000 without a prep.

Only three will line up against American Post, and one of them, Diamond Green, is capable of an upset.

Because of soft ground, the Andre Fabre-trained Diamond Green was scratched as the pre race favorite last October from the Prix Jean-Luc Lagardere, a race American Post won by four lengths. A half-brother to five French group race winners, Diamond Green is undefeated in three starts, the most recent in the Group 3 Prix La Rochette on Sept. 11. He will be ridden by Gary Stevens.

Aidan O'Brien will test the locals with Group 3 Railway Stakes winner Antonius Pius.

Also at Longchamp Sunday:

* Fabre will give Stevens a leg up on Grey Lilas in the Fontainebleau's filly equivalent, the Group 3 Prix de la Grotte. An improving Danehill filly, Grey Lilas cannot be expected to beat Denebola, the Pascal Bary-trained winner of the Group 1 Prix Marcel Boussac. Dalna, the unbeaten Head-Maarek-trained winner of the Group 3 Prix Miesque, also looms large.

* Last year, Dalakhani began his championship season with a victory in the Group 2, 1 5/16-mile Prix Greffulhe. This year's Prix Greffulhe prep contains nothing of his caliber. Day or Night, trained by Pease for George Strawbridge, is a Daylami colt who was third in the Group 1 Criterium de Saint-Cloud last November. He prepped with a win in a 1 1/4-mile allowance on April 1. An O'Brien-trained Irish invader, Esperanto, scored in a similar race two weeks ago.

But the race could boil down to a battle between Head-Maarek's listed winner Millemix and Vassilievsky, a full brother to Group 1 winner Vallee Enchantee.