A fan sitting courtside in Oklahoma City, feet from Cavaliers coach Tyronn Lue and well within earshot of James, had a message for the 12-time All-Star and four-time MVP near the end of the first half, with Cleveland leading 60-53.
"Just suck it up, LeBron!" bellowed a middle-aged woman, whose outburst could be seen and heard on the national TV broadcast as James lightly pleaded with the referee, arms outstretched.
For James' part, he didn't appear to immediately react to the fan's advice.
Later, though, a video clip of the sequence was published to his Instagram account, @kingjames.
"I guess she told me!! Hahahaha," the accompanying text read. "#JustSuckItUpLeBron #NoMomo #Classic."
The fan was reportedly Oklahoma's Judy Love, who according to Forbes is worth $2.4 billion.
The Cavaliers pulled away in the third quarter en route to their fifth straight win, with James putting up 25 points, 11 assists and 7 rebounds.
"These guys step up," Lue said of the Cavs. "They play hard, they play for each other. If they continue to do that, they'll be fine."
Information from The Associated Press was used in this report.