Duck Butter, a horse bred by Hobeau farm and named after an old groom who worked for Allen Jerkens, started it at Aqueduct back in December 1989. Trained by Bobby Lake, the 3-year-old ran in a $20,000 claimer with a new-to-New-York jockey aboard.

Harry Rice, a rookie valet, watched the race and had one thought as the jockey went left-handed in the stretch and Duck Butter won for the second time in 11 starts that year. “Whoa, who is this kid?”

The kid was Mike Smith, and while Duck Butter the horse didn’t get much further than that Aqueduct claimer, the kid went to the absolute top of the sport.

With Rice along for the ride.

When Smith won the June 9 Belmont Stakes aboard Justify to become Thoroughbred racing’s 13th Triple Crown winner, his valet was right there – watching with his son Harry – and soaking in the moment. Rice helped unsaddle Justify, collected Smith’s gear, headed for the scale, then carried the blue saddle, girths and helmet in the China Horse Club red and gold back to the jockeys’ room at Belmont Park.

“Unbelievable,” he said about halfway up the horsepath. “Ahh, it’s great. It’s a dream come true for him, for me. Twenty-nine years I’ve been with him and to see him ride an undefeated Triple Crown winner . . . I don’t get too emotional anymore, but it gets to me now and then.”

Oh it got to him. Three more times, Rice got emotional while saying he doesn’t get emotional anymore. There was a tear in his eye, a sniffle in his nose.

Out front, Smith, Bob Baffert, Kenny Trout, Teo Ah Khing and a slew of other owners celebrated in public – proud of their horse. Nobody was prouder than Harry Rice.

He remembered Smith’s early days in New York, the fame and fortune that followed, big victories, four consecutive 300-win seasons in the 1990s, a Hall of Fame induction in 2003, nasty falls, wicked injuries, long recoveries, an almost desperate move to California in hopes of saving a career and then another cycle back to the top as Smith teamed up with some of the best horses of the last 15 years. Rice – a NYRA valet at Aqueduct, Belmont and Saratoga – watched those last steps from afar, reuniting with Smith on the jockey’s trips to Belmont Park and Saratoga with the big names.

“I thought it was a great move,” Rice said of the relocation to the West Coast. “He had a chance to ride for some big outfits. They kind of forgot about him here a little bit, maybe he came back a little bit too quick from his injuries but it was a smart move and you see how good it worked out.”

Smith has arguably put together two Hall of Fame careers, one before his official induction announcement (while riding the likes of Holy Bull, Heavenly Prize, Lure, Inside Information, Skip Away, Coronado’s Quest and Prairie Bayou) and another after (Azeri, Arrogate, Songbird, Zenyatta, Royal Delta and so on).

It’s been a long ride, with plenty of scares to go with the success. Rice was there when Smith fell shortly after the start of a turf race late in the 1989 meet at Saratoga. Two days earlier, the jockey won the Travers aboard Coronado’s Quest. Smith led the standings with 30 wins and wound up with a broken back, in a body cast for months and out for the rest of that year. Rice saw it happen.

“You know the shape I’m in, I ran down there and I didn’t know who was going to get the oxygen first me or him,” the valet said. “He was spasming up because all the muscles were going up and down his back. He got up and walked to the ambulance, with a broken back. He’s that tough.”

For years, Smith has joked about riding “one or two more years.” Rice figures retirement will be awhile.

“He can go as long as he wants,” Rice said. “He rides good. He’s in the best shape, of any guy.”

Back in 1989, Smith was any guy – walking into the Aqueduct jocks’ room a fresh face in from Kentucky. He’d started out at Santa Fe in 1982, moved to Sunland Park, Oaklawn, Aksarben, Hawthorne, Canterbury, Arlington, Keeneland, Churchill Downs, wherever the horses and the rides were.

Then came New York.

Rice called Smith confident and humble. The jockey entered the competitive New York colony like he belonged. Another valet, Eddie Brown, was supposed to take Smith but had too much work. Rice, working with veteran Jean Cruguet at the time, was next in line.

“I was the new guy, so I got the new jock,” said Rice. “We’ve been together ever since.”

The valet and his wife Joan got married a few weeks earlier so Smith will always be second in the relationship race, but . . .

“He’s everything,” Rice said of Smith. “We’ve been through so much together. Injuries, deaths, stuff as people, things like that. It’s fabulous. I’m so happy for him and proud of him.”

Smith made his New York debut Dec. 6, 1989, finishing sixth aboard All Hands On Deck. The first win, with Duck Butter, came the next day. Another win, aboard Onnagata, followed the day after that. By spring, Smith was a New York fixture with a win aboard Thirty Six Red in the Grade 1 Wood Memorial. They finished ninth in the Kentucky Derby, but Smith was on his way.

Rice said his friend hasn’t changed much in the nearly three decades that have passed. OK, the 52-year-old no longer wears jeans you have to boil and starch but otherwise he’s the same guy.

“From the day he walked in, the weekend after Thanksgiving, he’s never changed,” said Rice. “He wears fancy suits now, but he’s just like he was then – humble, just like you see him in the interviews and things.”

Smith rides with patience, confidence, style. He makes quick decisions, stays out of a horse’s way, finishes with power and finesse. But there’s more to the success, according to his valet anyway.

“He’s never nervous,” Rice said. “The rides on Zenyatta, the ride in Dubai on Baffert’s other horse (Arrogate). He breaks dead last and Mike’s like ‘OK, we’ll just sit here and let it come to us.’ ”

And now Justify, who navigated through wins in the Kentucky Derby, Preakness and Belmont Stakes – joining Seattle Slew (and his jockey Cruguet) as the only undefeated Triple Crown winners in racing history.

After the clincher, Smith celebrated in the winner’s circle. He did interviews, posed for photos, met dignitaries, smiled, paid credit to his horse, the owners, Baffert, God, loads of people. Somewhere along the line, he thought of Rice too.

“We started together so that’s like having my brother, man, be there for it,” Smith said back in the jocks’ room. “It’s amazing to do it together. We’ve been so blessed to have done some wonderful things together but this is a dream come true for both of us. It’s wonderful . . . he even started crying.”

And he doesn’t get emotional.