We knew that President Obama was elbowed in a November 2010 basketball game.

We knew that, as a result, he needed 12 stitches in his lip.

But we didn’t know many details, until the Boston Globe’s Stan Grossfeld today told the whole story.

Reynaldo Decerega, who was born in Panama and came to the United States at age 6, is a lifelong hoopster who got invited to play with the president through a contact at One on One Basketball Inc., an outfit that schools people on basketball. Of the moment when Decerega connected with the presidential lip:

“He was crowding me,” [said Decerega]. “Instinctively, you crowd the person you’re guarding once he stops his dribble. And instinctively, as the offensive person, I felt the pressure, so I was trying to clear some space. You swing your arms to see what options you have.

“So I swung the ball from my left side to my right side. And in that swing — I’m obviously leading with this elbow — I hit him in the lip and he fell to the ground from the contact. And that’s a very surreal moment.”

The media swarmed Decerega’s house. “I left,” he tells the Globe.