LOUISVILLE, Ky. – John Shirreffs had to jump around. He just couldn’t help it.

The normally reserved trainer turns bashful when recalling his jubilant burst through the Churchill Downs grandstand two years ago after 50-1 shot Giacomo pulled off the second-biggest upset in Kentucky Derby history. Hall of Fame jockey Mike Smith expertly picked off horses down the stretch to win in the final yards.

“I just tried to not step on the person next to me,” Shirreffs said Tuesday. “I didn’t think I could get that excited, to be honest.”

It’s a moment etched in Shirreffs’ memory, one he hopes to relive Saturday when Giacomo’s half brother, Tiago, heads to the post in this year’s Derby.

The similarities are striking. The two horses come from the same dam, Set Them Free, with different sires: Giacomo from Holy Bull, Tiago from Pleasant Tap. Both are owned by Jerry and Ann Moss, ridden by Smith and trained by Shirreffs, the soft-spoken Southern Californian who just smiles when contemplating another unexpected run for the roses.

“There’s so many little connections, it’s just great,” he said.

Alike in temperament if not experience, Shirreffs can see some of Tiago’s older sibling in his 3-year-old chestnut colt, who won the Santa Anita Derby last month.

“Both are very focused and intense horses but they’re not real nervous types,” Shirreffs said. “They’re really racehorses. They love to run.”

Giacomo cemented his legend in the stretch at the Derby, roaring from 11th to victory in the final quarter-mile. It’s a move Tiago repeated in winning the Santa Anita Derby, as Smith moved Tiago wide to get some room then ducked to the rail to edge King of the Roxy by a half-length.

It’s a victory Shirreffs credited to Smith, who seemed to find the common ground between the two horses.