Duke's Zion Williamson celebrates after the Blue Devils beat Florida State on Saturday night for the ACC title. Williamson scored 21 points and was named the tournament’s MVP. (Nell Redmond/Associated Press)

Closing a splashy three-night show that proved 18-year-old Zion Williamson can serve as an asset on a basketball court, Duke won the ACC tournament on Saturday, handing a savvy Florida State only its second loss in 16 games since mid-January.

While the 73-63 win gave Mike Krzyzewski his record 15th ACC tournament title in his 39 seasons as coach at Duke and while it pretty much assured the Blue Devils (29-5) of a No. 1 seed in the NCAA tournament, what happened at Spectrum Center exceeded all that. Over three nights as Williamson returned from a 22-day injury absence and Duke played Syracuse, North Carolina and Florida State, the event gave a sort of demonstration of basketball evolution, how in the year 2019, humanity can fashion a 285-pound man who moves like an optical illusion.

That would be Williamson, whose 21 points and five rebounds in the final gave him 81 and 30 for the tournament. His field goal accuracy stood as one of the prettiest things anybody ever saw: 33 for 43. It marked the resumption of his sensation. In the final, the 6-foot-7, 285-pound, smart, quick, nimble, energetic, determined force didn’t quite make the plays that sent witnesses into primal screams and raptures the first two nights against Syracuse and North Carolina, even if he did dunk serially.

Instead, he regularly made basketball plays lovable even to a snooty connoisseur.

He threw a pretty interior pass from the perimeter to Cam Reddish for a simple first-half score. He threw an outrageous 50-foot bounce pass on a break from top of the key to top of the key, creating a Tre Jones second-half layup. He scrambled over to help with defense near midcourt, causing Florida State’s David Nichols to force an errant pass that led to a break that led to an RJ Barrett jam. He interrupted a lob that looked promising. He not only blocked a shot in the lane, but had the know-how to make a held ball out of it, with the possession arrow pointing toward Duke.

Seldom has the formal announcement of a tournament MVP seemed less necessary.

“I tell you, he has to be one of the top five best athletes that I’ve ever seen on the basketball court,” said Leonard Hamilton, the Florida State coach whose career began in 1966 at Gaston College in Dallas, N.C. Hamilton soon added, “So you can put him down as one of the greatest athletes that has ever come through the ACC, and there have been quite a few of them.” And Hamilton soon made this salient observation: “Zion can miss a layup, but he’s almost back up tipping it in quicker than anyone can realize the shot’s been missed.”

Williamson even played 39 minutes 56 seconds and looked so eager he might have suffered the four missed seconds. “I thought there was a good chance we would run out of gas,” Krzyzewski said of his four coveted freshmen. “A veteran player can be tired better.” Said Williamson of his return, “I want to be out there with them, and I made a commitment to them, and I would be a bad person if I went back on my commitment.”

Williamson, Jones, Barrett and Reddish were tired fine, even against the admirable Seminoles (27-7), a deep group often anonymous even in their own football town yet who barged to the last night of a basketball tournament with one giant and much glitterati. They gave a comprehensive thwarting to a probable NCAA tournament No. 1 seed, Virginia, on Friday night, shortly before Duke nudged by another possible No. 1 seed, North Carolina. When Florida State took a 27-19 lead on that potential third No. 1 seed, Duke, it looked as if the ACC could become that rare lot to accept three No. 1 seeds on Selection Sunday without any of them winning the conference tournament.

Florida State had brought along a contingent of fans so wee it looked like mostly next of kin, cheerleaders and a spirited two rows of trombones, tubas et al. Its scores often brought the din of cheering you hear at the 14th hole of a golf tournament. Had these fans wound up doing the unwise thing and stormed the floor, they might not have filled it. Yet a group of people seemingly almost as large had come along, and that would be the Seminoles’ roster of daydream collaboration in Coach Leonard Hamilton’s 17th season. Leading scorer: 12.8. Next up: 11.2, 9.1, 7.9, 7.6, 6.7, 6.5, 6.1 and 4.6. On a team of steep experience, with the 10-deep players amassing 865 college games of experience by one count, most of them contributed to an impressive near-secret: Florida State made the final eight last year.

It made sense, then, that as the Seminoles built their eight-point lead as a unit, with Trent Forrest’s three-point play, Mfiondu Kabengele crashing in to follow a miss, Kabengele raining in a three-point shot, Devin Vassell raining in another from a deep corner and Forrest getting a layup off his own steal, Krzyzewski called a timeout 7:28 before halftime.

Williamson jammed one as he will. Jones flicked a quick inbounds pass to Barrett for a three-point play. Williamson helped out with the defense on Nichols, and Barrett jammed. Williamson got inside for a foul and one free throw. Williamson got inside for a layup. By halftime, it was 36-36, yet Duke would upgrade still more from there. In a blurry sequence of talent and upgraded energy — “They imposed their will, their physicality on us,” Hamilton said — the Blue Devils would bust out to a 14-point lead by the 11:21 mark behind Jones (18 points), Barrett (17 points) and, yes, that 50-foot pass, a soft 17-footer and all manner of else from Williamson. .