Spurs center Victor Wembanyama, right, put up just the second 40-20 game in team history on Friday night on a night when the Knicks’ Jalen Brunson flirted with his own history.

Marvin Pfeiffer/Staff Photographer

The year after Victor Wembanyama was born in France, an ad man half a world away had an idea. He pitched a four-word catchphrase to his bosses, and those bosses brought it to the mayor of Cleveland, who declared it “art” so it could go up on a billboard 10 stories high.

“WE ARE ALL WITNESSES,” read the words next to a giant image of young LeBron James.

The slogan caught on, from the front of ubiquitous T-shirts to the taglines of international commercials. And even though the point was to sell shoes, the message resonated.

Sometimes, watching is a privilege.

Almost two decades after that first billboard was raised, there are times out there on the basketball court when Wembanyama still feels that way. He’s spoken often during his first five months in the NBA about how his up-close views of James, Kevin Durant, Joel Embiid and Nikola Jokic have left him “inspired.”

And on nights like Friday, when yet another Spurs opponent put on a history-making show? Wembanyama has no intention of taking it for granted.

“I’ve just witnessed so much greatness,” Wembanyama said, “and I want to be a part of it.”

This is how a witness becomes the spectacle. He watches excellence with admiration. He lets it soak in. Then he tries to top it, whether it’s by leading comebacks against James and Durant, or trading freakshow drives with Giannis Antetokounmpo, or one-upping a career night by the Knicks’ Jalen Brunson with one of his own.

None of these epic back-and-forths are coincidences.

In overtime at Frost Bank Center on Friday, when Brunson swished a jumper to give him 61 points in the game — the second-highest total in New York franchise history — it took Wembanyama a matter of seconds to respond with a milestone of his own. When he drained a 3-pointer at the other end of the floor, it gave him 40 points to go with 20 rebounds, and it proved to be the finishing touch on a 130-126 Spurs’ victory.

“It’s become very normal of him,” Spurs teammate Tre Jones said. “When everybody (else) is having their big games, he’s going to be doing his thing, always.”

Wembanyama’s rookie-season track record bears this out. Before Friday, his best scoring night came in his national TV coming-out party in Phoenix, when he poured in 38 against Durant and the Suns in November. Some of his most memorable highlights of the year came against Antetokounmpo, also on TNT, in a down-to-the-wire loss to the Bucks. And although the Rookie of the Year award has been his to lose all along, Wembanyama removed all doubt by scoring 28 points in a February victory over Oklahoma City that he iced with a stone-cold rejection of the leading contender, Chet Holmgren.

It’s as if proximity to something spectacular brings more of it out of him, which isn’t a bad quality to have if you’re the type of guy who expects to be competing for championships in the years to come. Even so, there are exceptions. Wembanyama hasn’t risen to every moment, and he had occasion on Friday to reflect on one that escaped him.

Way back in early November, in one of Wembanyama’s first road games in the league, he arrived at Madison Square Garden a bit awestruck by the scene. He knew the history, and one of the biggest media contingents of the year were there to greet him. But in that first game against the Knicks, he slogged through a mostly forgettable 14-point, nine-rebound, 4-for-14 night in a blowout loss, and by the end of it the crowd was chanting “Overrated!” from the nosebleed seats.

“I would say (that) game embodied a lot of our weaknesses,” Wembanyama said Friday. “We’ve been able to erase (them) a little bit throughout the season, more and more. This is the type of contrast we want to see in this season.”

Friday night, that contrast became as apparent as ever. Once again there were Knicks fans howling, this time as guests scattered throughout the Spurs’ home arena, and once again there was a moment when it looked like the whole thing could slip away from Wembanyama.

But as Brunson kept blowing by defenders and swishing jumpers, looking bound for a performance that would live in Knicks’ lore forever? Wembanyama, long an enthusiastic witness to greatness, became an author of it.

It won’t be the last time.