Kentucky Derby
A woman has won millions thanks to the Kentucky Derby. Horses are pictured running the race at Churchill Downs on May 6, 2017 in Louisville, Kentucky. Patrick Smith/Getty Images

[Correction: Longshot Country House (65-1) won the Kentucky Derby after an objection. It was previously noted that Maximux Security had won.]

In a historic reversal, Maximum Security splashed through slop Saturday to cross the line first at the 145th Kentucky Derby at Churchill Downs, but the result was changed with longshot Country House taking the title after an objection.

Country House, trained by Bill Mott, stunned the crowd when it was announced after an over 20-minute wait for a video replay. There were loud boos heard from the over 150,000 in attendance at Churchill Downs.

It was just the second disqualification in Kentucky Derby history and the first disqualification for a first-place finisher.

Meanwhile, Country House became the second biggest longshot to win the race. The victory also gave Mott his first Kentucky Derby win.

Mott called the victory "bittersweet" because of the disqualification.

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Maximum Security was disqualified for impeding War of Will by coming close to clipping his heels.

"We determined that the 7 horse drifted out and impacted the progress of Number 1 (War of Will), in turn, interfering with the 18 and 21 (Bodexpress). Those horses were all affected, we thought, by the interference," said Barbara Borden, chief steward for the state of Kentucky.

Maximum Security owners Gary and Mary West said they might appeal.

Trained by Jason Servis with Luis Saez as the jockey, Maximum Security entered the 19-horse race as the 4-1 co-favorite. The Florida Derby winner came into Churchill Downs with a 4-0 record.

Because of the disqualification, Code of Honor (14-1) finished second, followed by Tacitus (5-1) and Improbable (4-1).

It was a disappointing day for famed trainer Bob Baffert, who was hoping to capture his sixth Kentucky Derby title and had three serious contenders.

The Preakness, the second leg of the Triple Crown, will take place on May 18 at Pimlico Race Course in Baltimore.