The main event of this year's Breeders' Cup World Thoroughbred Championships, without a doubt, is the Classic. The 23rd renewal should live up to its name at Churchill Downs.

During five previous BC Days at the historic Louisville track, there have been exciting Classics: Tiznow edged Giant's Causeway by a neck in 2000, Awesome Again defeated Silver Charm by three-quarters of a length in '98 and Alysheba beat Striking the Gold by a half-length in '89.

So don't be surprised when the margin of victory is less than a length on Nov. 4. That's because the top contenders are classy campaigners on winning streaks:

Lava Man: The 5-year-old gelding has captured six stakes in a row during '06, including four Grade 1 races, and earned nearly $2.5 million. Four victories were at the Classic distance of 1 ¼ miles while two were on the turf.

With five wins on the grass it's no surprise his final prep on Saturday comes in the $250,000 Clement Hirsch Turf Championship at the Oak Tree at Santa Anita meeting.

The son of Slew City Slew faces another gelding three years older who also is undefeated - the Tin Man, winner of this race in '02. His latest score in three outings: the Arlington Million in wire-to-wire fashion.

Bernardini: The top sophomore has registered five consecutive triumphs since his fourth-place career debut back in January at Gulfstream Park, but it was a sprint.

Three Grade 1 wins include the Travers at the Classic distance and the Preakness, with earnings exceeding $1.6 million.

The A. P. Indy colt that has likely clinched 3-year-old championship honors is on a collision course with one of his BC Main Event foes in the $750,000 Jockey Gold Cup at Belmont Park on Oct. 7.

Ivasor: The 4-year-old colt has not tasted defeat since a fourth-place finish in the UAE Derby at Dubai back in March and is 8-for-9 during his career, including two victories at the BC Classic distance.

His three consecutive wins are all Grade 1s - the last two after horrible starts. The son of Candy Stripes finished ahead of Sun King and West Virginia in the Whitney, in front of Wild Desert in the Suburban and bested Wanderin Boy in the Pimlico Special. He has banked more than $1 million this year.

Other horses that may try their luck in the Classic are:

Sun King: The 4-year-old hit the board in his last five outings, but hasn't won since taking the Commonwealth at Keeneland in April. The son of Charismatic did come within a nose of Ivasor in the Whitney.

Dylan Thomas: Winner of the Irish Derby and Irish Champion Stakes goes in the Jockey Cup Gold Cup. It will decide whether the 3-year-old runs in the Classic.

Flower Alley: Last year's Classic runner-up behind the late Saint Liam has turned in two disappointing efforts and future plans for the son of Distorted Humor are up in the air.

Perfect Drift: This warhorse, thir din the '05 Classic, has not visited the winner's circle in five '06 outings. But the 7-year-old son of Dynaformer won or placed in 24 stakes during his 40-race career, earning more than $4.5 million.

Jazil: Impressive winner of the Belmont Stakes has been sidelined several months with a bruised hind cannon bone, but recently began jogging 1 ½ miles. But it appears doubtful the 3-year-old son of Seeking the Gold will go in the Classic.