The San Antonio Spurs' top pick explained his side of the situation to KENS 5 reporter Nate Ryan shortly after a workout on Thursday afternoon ... saying it all went down as he was walking into Catch restaurant in the ARIA Hotel in Las Vegas.

Wembanyama -- the most touted basketball prospect since LeBron James -- said there were a lot of people in the hallway near the eatery calling for him ... but he was instructed not to stop in order to avoid creating a chaotic scene.

One woman, though, kept asking for him ... before she ran up to him and put her arms around him.

He later learned that person was Spears.

"I didn't see what happened, because I was walking straight and we were told, 'Don't stop,'" Wembanyama said. "But that person grabbed me from behind -- not on my shoulder, she grabbed me from behind -- and so I just know the security pushed her away."

"I don't know with how much force, though. But security pushed her away. I didn't stop to look so I could walk in and enjoy the nice dinner."

Wembanyama said he didn't know the woman was Spears until "a couple hours later" because he never saw her face.

"At first I was like, 'No, you're joking,'" he said. "But, yeah, it turns out it was Britney Spears."

Spears' husband, Sam Asghari, also addressed his side of the incident in a pair of Instagram posts Thursday afternoon ... chastising Wembanyama's security guard for getting physical with the singer during the incident.

"The violent behavior of an out-of-control security guard should not cast a shadow on the accomplishment of a great young man on the rise @wemby," he said. "The blame should fall on the coward who did this, the people who hired him without proper vetting, and a systemic culture of disregard for women within sports and entertainment."

Sam went on to say he believed Spears was "physically assaulted," and he demanded to see changes "come from the top."

"And I look forward to those changes," he said.