Trainer Jean-Claude Rouget and jockey Christophe Lemaire have an excellent chance of winning their third French classic this year at Chantilly on Sunday. Stacelita is the likely favorite in the 12-runner Prix de Diane, or French Oaks, for fillies at 1 5/16 miles.\nThe pair combined to win the French 1000 Guineas with Elusive Wave and last Sunday's French Derby with Le Havre.\nStacelita has the qualifications to add to that tally. She is unbeaten in four races, and her winning margins have increased as the competition has grown stronger.\nShe started with a couple of wins by two lengths in the provinces and then stepped up to a listed stakes on her first visit to Paris, winning by four lengths.\nA daughter of the top German stallion Monsun, Stacelita attracted attention with her six-length victory over Article Rare in the Group 1 Prix Saint-Alary at 1 1/4 miles at Longchamp on May 17. The turf was soft that day - which suits her well - and it promises to be on the soft side again Sunday.\nRouget also runs Tamazirte, who finished a half-length second to Elusive Wave in the 1000 Guineas on May 10. She will again be ridden by Ioritz Mendizabal.\nHowever, the third-place finisher in the Guineas is likely to give Stacelita the most trouble. Fantasia, owned by George Strawbridge, finished 1 1/2 lengths behind Tamazirte and made little impact in the straight after chasing the front-running winner from the start.\nFantasia was a Group 3 winner last year and added the Group 3 Nell Gwyn Stakes by an impressive seven lengths over what has turned out to be a bad field at Newmarket in April.\nBoth of those races were seven furlongs, and Fantasia was beaten at one mile at Longchamp. However, the Luca Cumani-trained Fantasia is by Sadler's Wells out of a mare by Darshaan, so this longer trip should be just what she needs.\nStacelita is not the only unbeaten filly among the 12 runners. Celimene also holds that distinction. She is trained by Carlos Lerner and will be ridden by his son, Yann. The trainer won a French Derby in 2001 with Anabaa Blue and finished second in the Diane with Volvoreta in 2000.\nHowever, Celimene has not run since the Group 3 Prix Penelope on April 13, and the fillies she beat have since been put to the sword by Stacelita. Celimene's connections will be hoping that the ground stays soft.\nDenomination may prove best of the rest. A Smart Strike filly bred by Brookdale Thoroughbreds, she disappointed last year by scoring only once in six tries. But she has won both her races this year - a listed and a Group 3 - and has sound claims for a place.\nAlso entered are Celebra, Board Meeting, and Shediyama, whose dam, Shemaka, won the Diane in 1993. That trio will need to make considerable improvement.