Conduit etched his name in Breeders' Cup history when winning consecutive renewals of the Turf at Santa Anita on Saturday night.
Sir Michael Stoute's four-year-old had to work a good deal harder then when winning 12 months ago and Ryan Moore excelled on the chestnut.
Presious Passion set his usual frantic early pace but came right back to the field turning into the straight.
However, Elvis Trujillo had given the American challenger a canny ride and he kicked on again.
Conduit kept up his relentless charge though and finally broke the heart of Mary Hartmann's six-year-old.
Dar Re Mi claimed third with Spanish Moon, stablemate of the winner, fourth.
Stoute said: "It's always a big day and these are the world championships. This is a very important race and it's great to see him go and win it twice in a row.
"We're thrilled with him and we're also pleased with the fourth horse, Spanish Moon.
"It was a messier race this year so I wasn't as confident this time, but under the circumstances it was just as good a performance.
"The plan has been to come back here since last year.
"He won't stay in training next year as he is going to go to stud in Japan. The Japan Cup is on his agenda before then though.
"We'll see how he comes out of this and take a look and see how he handles the return journey, but we would like to take him to Tokyo and I would like to express my delight to Ballymacoll Stud who are just a small operation in Ireland but have just an amazing record in this race.
"It was a good performance from Spanish Moon, he was just behind Dar Re Mi which is top-class international form."
Moore added: "I didn't want to go wide and then get beat but luckily the opportunity was there for him.
"He wasn't fast away and I was in behind Red Rocks and Telling which are not the sort of horses you want to be tracking round.
"I got forward in the straight and I used a bit of petrol but to be fair to the horse, he was very game.
"He's been a great horse for me and sort of a once in a lifetime horse. I believe he's going over to Japan now and we'll see how he gets on there."
John Gosden said of Dar Re Mi: "On form she's run bang to her rating.
"There was a little bit of scrimmaging on the bend and she got tightened up. I still think she'd have been third but she would have been a little bit closer.
"She's run a tremendous race but I've no idea if she stays in training."
Her rider Frankie Dettori said: "I was very pleased with the filly. Conduit beat us a length in the Arc and has done the same today. He just had more cruising speed and that finishing kick."
Kieren Fallon added of Spanish Moon: "I was in a difficult position to judge which way to play the leader who is tough and doesn't come back. It was very hard to get it right, as I didn't want to get there too soon. In the end I didn't and Conduit did."
Hartmann said of Presious Passion: "I thought he ran his race. He laid it all on the line and just got caught.
"He fought back and just doesn't like to let them go by."
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