LAS VEGAS — The buzz began before noon local time Friday, well before the first of 10 games tipped off on the opening day of the Las Vegas Summer League.

A hot sun was beating down on the concrete, though it did little to discourage the never-ending line of fans that zigzagged around the Thomas & Mack Center. Most of the sold-out crowd was there for one reason.

The Zion Williamson show was in town.

In a city that advertises shows of all kinds, this was unlike any other — for reasons nobody expected. The game was postponed in the fourth quarter as the Vegas area was rocked by the effects of a 7.1-magnitude earthquake.

In front of a packed house, playing against his former Duke teammate RJ Barrett and the Knicks, Williamson made his pro debut and racked up 11 points and three rebounds in the first half before sitting out the second with a left knee injury. The No. 1 pick took a knee-to-knee hit, and while it was not expected to be serious, according to ESPN, the Pelicans played it safe and held him out for the rest of the game.

After the earthquake cut the game short, Williamson left the arena without speaking to the media. He did not appear to be wearing anything on his left knee.

As Williamson sat on the bench in the second half, chants of “We want Zion” came and went, to no avail. But the 6-foot-7, 285-pound phenom gave the fans a glimpse of what they came for in just over nine minutes of action.

All Williamson had to do was dunk once in the pregame layup line and the place went wild.

The celebrities in attendance ranged from fellow NBA players LeBron James, Anthony Davis, Lonzo Ball, Trae Young and No. 2 pick Ja Morant to Floyd Mayweather.

Williamson got off to a slow start, capped off by an air-balled jumper, but he quickly gained steam. First there were two-handed slams on back-to-back possessions. Then he had a one-handed swat the crowd roared for, making it was too loud to hear the whistle for goaltending.

Soon after, Williamson wrestled a ball out of Kevin Knox’s hands and took two steps for another dunk that brought the crowd to its feet.

There were more boos when Williamson got fouled in the open court, robbing him of a chance at one of the jaw-dropping dunks that helped him take over the college basketball scene at Duke and rise to the top pick in June’s draft.

A regular dunk just before the buzzer at the end of the first quarter put Williamson at 10 points. He finished with 4-of-9 shooting, including 0-for-2 from beyond the 3-point arc.

While the crowd seemed a bit deflated whenever Williamson was on the bench, it was equally raucous whenever he stood up to walk to the scorer’s table and check in. The next check-in never came, but the roars will be back whenever it does.