But Zion Williamson, the projected No. 1 pick in June's NBA draft, claimed he didn't notice the buzz or the NBA All-Star.
"LeBron was out there?" Williamson asked after the game. "I didn't see LeBron."
Then one of his teammates yelled, "That's your big brother!" Williamson replied: "Stop it, bro."
It seemed as if Williamson was simply trying to avoid producing any headlines that would center on him. But his teammates all said they saw James and Rondo but tried to ignore them and stay locked into the game.
"I mean, we noticed, but you definitely still got a game to win, so we're focused," said forward RJ Barrett, who finished with a game-high 26 points after he made 60 percent of his 3-point attempts (6-for-10).
Blue Devils guard Tre Jones said he was more startled to see Rondo, one of his idols, than James.
"I didn't notice until probably the second half. It's hard to miss [James] when he stands up," Jones said. "A guy who was there, Rajon Rondo, is someone I've been watching since I was really young. I've always loved his game. Just as a point guard, he's always been able to control the game."
James, Rondo and the Los Angeles Lakers will face the Philadelphia 76ers on the road Sunday afternoon (3:30 p.m. ET, ABC).
Blue Devils coach Mike Krzyzewski said James told him he planned to attend the game, a high-stakes matchup between a pair of powerhouses that might help Duke seal the No. 1 overall seed in the upcoming NCAA tournament. Krzyzewski developed a bond with James when he was the head coach of the U.S. men's national team.
"He texted me today that he might be here," Krzyzewski said after the game. "So he and I are really good friends. And he helped me look good in Beijing and in London. So he's welcome to come around any time. But it was cool he was here."
In Saturday's second half, James was sitting underneath Duke's basket with Rondo and some of his friends, including his agent, Rich Paul. James was dribbling a basketball and laughing as the Blue Devils poured out of the locker room for warm-ups.
James tossed the ball to one of the team's managers and found his seat.
The Blue Devils didn't let the appearance of two NBA stars or a hostile crowd rattle them Saturday night.
"They're very talented players, love watching them," Duke center Marques Bolden said. "But we just tried to keep playing our game. We knew nobody else was gonna win the game for us, so we just tried to keep our composure and play the rest of the 20 minutes."
Barrett drops 26 in win vs. Virginia
RJ Barrett, Zion Williamson and Cam Reddish combine for 61 points as No. 2 Duke beats No. 3 Virginia 81-71.