The pressure of a game-winning free-throw attempt?
No, the birth of his son on Wednesday morning.
"I was doing good for the whole delivery until the end," said Powe, a former Oakland Tech High and Cal star now in his second season with the NBA's Boston Celtics. "Then they showed me the baby coming out, and I almost passed out. That was just too much. My legs were weak. I had to go sit down."
Powe said the delivery by his girlfriend of 21/2 years, Llorren Cook, went smoothly. Leon Powe III arrived at 21 inches and 7 pounds, 14 ounces.
"He's got big hands. They cover his whole face," Powe said.
Powe, who grew up without a father, said he embraces the opportunity to raise a son.
"Oh man, it feels great," he said. "It's great having a kid and being able to try to lead him in the right way, show him all the right things.
"This was a real new experience for me, overwhelming, but one to remember. This was amazing."
Powe, who turns 24 on Tuesday, has had a less eventful time on the court for the NBA's winningest team. He's played in just 14 of the Celtics' 37 games, averaging 2.6 points and 1.4 rebounds in 4.3 minutes.
Powe said he continues to work hard and tries to benefit from playing alongside all-stars Kevin Garnett, Paul Pierce and Ray Allen.
"I just try to learn from all of them," he said.