The last person a hospital storekeeper expected to see across the mat during a Brazilian jiu-jitsu event in May was Meta CEO and Facebook founder Mark Zuckerberg.

Zuckerberg was facing off against Jeff Ibrahim, 40, a California man who picked up the combat sport last winter to bond with his 8-year-old son Jameson.

That day would make for a "hell of a story" Ibrahim would never forget, he told NPR Monday.

"I mean, whatever politics people have regarding Zuckerberg, he came across to me like, he was a cool dude," Ibrahim said. "I just looked at him like he was just another person who wanted to compete in jiu-jitsu. And the one thing that people don't understand, the hardest part is stepping on a mat to compete in front of hundreds or thousands of people. And, you know, I have to give him his props. He did that."

A family affair

Discipline has been at the heart of Ibrahim's jiu-jitsu training since he embraced the sport in November.

Ibrahim and his son trained roughly four days a week — which, during the first two months, left him sore almost every day, he said.

After losing his first competition in the 170-pound weight class in February, Ibrahim dropped down to 150. This gave him the confidence he needed to enter a jiu-jitsu competition in Woodside, Calif., on May 6 with his son, Ibrahim said.

"I signed up just because my son was going to compete. So it's always been like, a dream for him and I to win gold medals on the same day, and represent our academy, Ralph Gracie Jiu-Jitsu Richmond," Ibrahim said.

Ibrahim won his first match — and was on to the gold medal round — when he found himself standing near his next opponent, Zuckerberg.

"He's asking me questions about how long I've been competing for doing jiu-jitsu. And I actually remember that he's really into MMA. So we just start talking about that. He came along pretty friendly, actually," Ibrahim said.

An unforgettable faceoff

Ibrahim's match against Zuckerberg began around 4:45 p.m.

At the start of the roughly 2-minute-long bout, Zuckerberg can be seen pulling on Ibrahim and leading him around the mat before dragging him down.

"Basically, he pulled me and when I got on top of him, his legs were wrapped around me," Ibrahim said. "He's pulling the sleeve of my uniform, to the point where my uniform almost comes off, because I'm trying to get out of his guard. His technique was decent. I was able to actually get out of his guard, or as we call it, passing the guard. I was able to get out of it, and then switch positions. But then he ended up kind of pulling me back into his guard, but it wasn't tight enough."

Ibrahim then got Zuckerberg in an Ezekiel choke, which caused the tech entrepreneur's face to turn red and then purple, Ibrahim said.

"I wasn't going to let go of it until one, he tapped out, or two, the referees stopped me. And I felt that he never tapped out. I couldn't tell if he was making any noises or anything. ... I was just in the zone. I mean, he was trying to get out of it, but like the grip that he had on me, it just kept getting looser and looser," Ibrahim said.

The next thing Ibrahim recalled was feeling the referee tapping him on the back to stop the match, he said. Video captured by Ibrahim's wife shows Zuckerberg rising to his feet after Ibrahim released him.

"At no point during the competition was Mark knocked unconscious. That never happened," a Meta spokesperson said in a statement.

A perplexed Zuckerberg can be seen talking to the referee while the latter raised Ibrahim's arm in victory.

"Mark was confused originally, then that's when the referee explained it to him. And then he just shook his head and like, 'OK, I got it. I understand.' We shook hands. Gave a little bro hug," Ibrahim said.

It is unclear in the video why the match was stopped and what the referee told Zuckerberg following it.

That hug would be the second most important one Ibrahim gave that day. The first was for his son Jameson, who also won a gold medal at the event.

"Seeing him win gold in his division was one of the best moments in my life," Ibrahim said. "He works so hard with his jiu-jitsu . ... Now he knows how hard work pays off. Our relationship and bond is a lot stronger because of jiu-jitsu."

Brin Winterbottom contributed to this report.