Lure Is Upset in Lexington Stakes : Kentucky Derby: My Luck Runs North beats heavy favorite by a neck in the mud. Arazi works 1 1/8 miles in France.

The 118th Kentucky Derby gained another entrant Tuesday when My Luck Runs North, a colt who once ran for a $16,000 claiming price in Florida, upset 2-5 favorite Lure by a neck in the $134,550 Lexington Stakes on a muddy track at Keeneland.

After the 1 1/16-mile race, trainer Angel Medina said that My Luck Runs North will run in the Derby at Churchill Downs a week from Saturday.

My Luck Runs North’s appearance in the Derby strengthens the likelihood that a capacity field of 20 horses will run, even though Arazi is expected to be heavily favored. Should the owners of more than 20 horses want to run, Churchill Downs will invoke a rule that allocates starting spots based on money earned in graded stakes.

At least 21 horses are still under consideration for the Derby. They are:

Arazi, A.P. Indy, Technology, Dr Devious, Pistols And Roses, Pine Bluff, Conte Di Savoya, Lil E. Tee, Devil His Due, Treekster, West By West, Al Sabin, Disposal, Thyer, Casual Lies, Dance Floor, Snappy Landing, Sir Pinder, Ecstatic Ride, Hickman Creek and My Luck Runs North.

Allen Jerkens, who trains Devil His Due, has told Lenny Hale, a New York racing official, that his colt will run in the Derby. After Devil His Due’s victory Saturday in the Wood Memorial at Aqueduct, Jerkens indicated that the Derby might be too much hard racing in a short period of time for his colt.

My Luck Runs North, who went off at 7-1, passed Lure at the eighth pole under Ricardo Lopez and won in 1:44. Lure was four lengths ahead of Agincourt in the five-horse field. Alydeed and the undefeated D.J. Cat were scratched and their trainers are aiming for the Preakness Stakes at Pimlico on May 16. Before that, Alydeed is expected to run in the Derby trial on Saturday at Churchill Downs.

My Luck Run North has won six of 11 starts. As a 2-year-old, his first five starts were in claiming races.

At Chantilly, France, on Tuesday, Arazi outclassed two stablemates while working 1 1/8 miles in his final French preparation for the Derby. Arazi will be flown to the United States this weekend and is scheduled to arrive in Louisville on Sunday.

With Steve Cauthen aboard Tuesday, Arazi worked with American shoes over a left-turn course, the same kind he will face at Churchill Downs, where he won the Breeders’ Cup Juvenile in November. The French do not time their workouts.

“I wish his pace-makers had stayed with him more,” said Francois Boutin, Arazi’s trainer. “I would have liked it better if they had given him more to do, because he has a tendency to pull himself up.”