Everyone expected Curlin to grow up, but few expected the precocious winner of three of four starts to grow up quite so fast or quite so strong. Certainly no one expected the horse to transform in the middle of the Preakness Stakes. Curlin, having been passed on the turn as if he were standing still by Kentucky Derby winner Street Sense, dug in hard and rallied back to get the nod.

It was not an easy ride.

Curlin stumbled out of the gate. Robby Albarado, up in the irons, steered the horse toward the rail, looking for a place to settle into stride. But Robby said that Curlin “had trouble negotiating the turns,” and the horse angled out to hit the backstretch running four wide.

From the replays, Curlin’s interest looks sporadic. He was running very green, and Albarado had to drive him to keep him in the game while the pacesetters blazed through the opening fractions.

As expected, Xchanger and Flying First Class played the only card they had and came careering out of the gate to notch the first quarter in 22.83 seconds and the half in 45.75. That’s a very fast pace for a 1 3/16 mile race, and it was clear that neither of them would hang on until the end. Hard Spun chased them from a comfortable third until the final strides of the back stretch, and when the clock ticked 1:09.80 for six furlongs, it was Hard Spun’s nose setting the time.

When Street Sense charged to the lead, it looked as if the race was his. Borel had threaded a needle with the horse, and Street Sense was running his race, closing in the last quarter mile like a slamming door. He seemed unbeatable.

But something in Curlin woke up. Perhaps he saw a target, or perhaps something just clicked. Most horses, when passed like that, become discouraged. At the risk of over anthropomorphizing Curlin, it seemed that rather than becoming dispirited, he became incensed.

Showing unbelievable heart, the horse dug in and came back at the leader, gaining with every stride, and put him away at the wire. Today, Curlin certainly looks like he’s worth the chunk of change dropped by the joint owners Jess Jackson, Satish Sanan, and George Bolton to buy a part of him from Midnight Cry Stables after his maiden victory earlier this year. Not only did they just cash a $600,000 check, bringing his total earnings to just more than $1.6 million, they look now to be the owners of a very high quality stakes horse.

“The first part of the race he felt like a 2-year-old,” Albarado said, “the last part of the race he felt like a 5-year-old.”

Watching him wear down Street Sense leaves no doubt as to his future. He’s growing into a Grade 1 horse, and while he might not have been ready for the deep water when he loaded into the gate at the Derby, he certainly appears ready for it now. This was no fluke; Curlin is turning into something real.

I would like nothing more than to see the best horses back on the track in a few weeks at Belmont Park — and the two-time trifecta of Street Sense, Hard Spun, and Curlin in the Derby and the Preakness leaves no doubt at all about which are the best horses of this generation. But Carl Nafzger, trainer of Street Sense, seems to have lost all of the cool he displayed immediately following his defeat in the Preakness and come into something more sour.

“We only needed a nose,” said Nafzger, “Curlin ran a hell of race but we had him. We should have never let him come back and get us.”

An interesting turn of phrase, but I don’t exactly think Street Sense “let” Curlin win the race.

When asked about the Belmont Stakes, he said:

“I’ll talk to [owner] Mr. Tafel, but if I was a betting man I’d take some bets against it,” before adding the absurd comment that “winning isn’t everything in this game.”

“Heartbreaking, that’s what it was,” he said.

Heartbreaking? You lost the Preakness by a head. If winning isn’t everything, get back on the track, your horse just won $200,000 running an excellent race in one of the fastest Preakness Stakes of all time.

Let’s see them go back at each other in the Belmont Stakes. Let’s see the stretch duel. Everyone thinks this sport needs a hero. What about a rivalry? What about some real competition? Isn’t a thrilling race, a duel on the stretch, and an even match what we all came to see?

Have some guts and run them back.

Before the Preakness, Nafzger was praised for his patient handling of the press circus that attaches itself to the winner of the Kentucky Derby. He replied wonderfully, saying that Street Sense was everybody’s horse now.

That’s what happens when you win the Derby, the nation adopts your horse. The nation should be allowed to keep him at least until someone is standing in the winner’s circle out at Belmont. Losing the Preakness isn’t heartbreaking, losing the potential rematch of Curlin and Street Sense is.

mwatman@nysun.com