AP photo John Velazquez riding Medina Spirit, right, leads Florent Geroux on Mandaloun and Flavien Prat riding Hot Rod Charlie to win the 147th running of the Kentucky Derby at Churchill Downs, Saturday in Louisville, Ky.

LOUISVILLE, Ky. (AP) — John Velazquez was in a familiar place, in the lead aboard Medina Spirit in the Kentucky Derby and holding off the stretch bid of three challengers. This time, Bob Baffert couldn’t believe what he was seeing.

Medina Spirit won by a half-length on Saturday, giving Baffert his seventh victory, the most of any trainer in the race’s 147-year history.

The jockey and trainer — both Hall of Famers — teamed up eight months ago to win a pandemic-delayed Derby in September with Authentic, who raced to an early lead and hung on. That wasn’t so surprising.

This one was.

Sent off at 12-1 — astronomical odds for a colt trained by the white-haired, two-time Triple Crown winner — Medina Spirit was in a street fight thundering down the stretch.

The dark brown colt was pressed by Mandaloun on his outside. Hot Rod Charlie was coming fast outside of Mandaloun, with 5-2 favorite Essential Quality chasing on the outside.

Velazquez knew he had plenty of horse left.

“We got to the 16th pole and he put his ears down and kept fighting,” the jockey said. “I was so proud of him.”

In the paddock, Baffert watched in amazement as one of the least heralded Derby runners of his long career dug in at the front.

Medina Spirit led all the way and ran 1 1/4 miles in 2:01.02. He paid $26.20, $12 and $7.60. The victory was worth $1.86 million.

Velazquez earned his fourth Derby victory aboard the colt that was purchased as a yearling for $1,000 and was a bargain-basement buy at $35,000 for current owner Amr Zedan of Saudi Arabia. By comparison, Zedan recently paid $1.7 million for an unraced 2-year-old.

Baffert punched his right arm in the air after watching the finish on the video board. He was buried in celebratory hugs by his wife, Jill, and youngest son, Bode. Jill Baffert had reason to celebrate earlier, when a horse she co-owns and is trained by her husband won a $500,000 race on the undercard.

It wasn’t false modesty. Baffert had been low-key about his chances after two of his best horses — Life Is Good and Concert Tour — were derailed along the Derby trail.

Medina Spirit isn’t the typical high-priced talent with a fancy pedigree in Baffert’s California barn.

Medina Spirit has never finished worse than second in six career starts and two of his three losses came to Life Is Good, who likely would have been the Derby favorite had he not been injured.