DEL MAR, Calif. — Arrogate and Gun Runner square off again in the $6 million Classic on Saturday, the marquee event on the second day of the Breeders’ Cup, which is being run for the first-time at Del Mar.

The 13-race, season-ending championships started with four races Friday. Nine more will be run on Day 2.

The event culminates with the Classic, the biggest event in the history of the seaside track north of San Diego.

Arrogate, the defending champion, is winless since the $10 million Dubai World Cup in March. He’ll need to be in peak form to handle Gun Runner, the 9-5 favorite.

The 2-1 second choice, Arrogate is one of four Classic entries for Bob Baffert, who has won the race the last three years, including with Bayern in 2014 and Triple Crown winner American Pharoah in 2015.

The all-time richest horse with earnings of $17.3 million, Arrogate followed the Classic victory with triumphs in the $12 million Pegasus World Cup and in Dubai.

Then things went south.

The 4-year-old gray is winless since his return from the Middle East. He was a badly beaten fourth as the 1-20 favorite in the San Diego Handicap, and second to stablemate Collected in the Pacific Classic in August over the same Del Mar track.

“I think a lot of it is the way I prepared him,” Baffert said. “I take the blame for him getting beat the first time. The second time, it looked like he wasn’t going to run and all of a sudden he started running at the end.

“I think he should run well.”

Arrogate beat Gun Runner by 2 lengths in Dubai. It’s been a dramatically different story since then. Gun Runner reeled off dominant wins in the Stephen Foster Handicap at Churchill Downs and in the Whitney and Woodward Stakes at Saratoga.

“Gun Runner is the horse to beat,” conceded Baffert.