The attacker struck in a flash, pie dish in hand. A scuffle broke out, shaving foam flew.
James Murdoch sprang up, astonished. His father stayed seated, unfazed.
The moment of slightly farcical drama in Parliament on Tuesday highlighted the contrasting styles of the blunt, combative media mogul Rupert Murdoch and his smooth, Harvard-educated son.
The 38-year-old son appeared eager to answer questions, but it was his father who increasingly dominated a session designed to show British lawmakers _ and News Corp. shareholders _ that the 80-year-old mogul remains firmly in control.
Rupert Murdoch has never before appeared in front of a parliamentary committee _ his son gave evidence in 2009 _ and both Murdochs tried to avoid it this time around. They initially declined to come and answer questions about lawbreaking at their now-closed tabloid News of the World, only agreeing once legislators dispatched a sergeant-at-arms with a summons.
They clearly decided contrition was their best hope for winning over the committee, disgusted readers and worried investors.
Rupert Murdoch said he was "shocked, appalled and ashamed" at the hacking of the phone of a murdered schoolgirl. This was "the most humble" day of his life, he said.
But if he was humbled, he didn't look it. Sitting beside his son in front of a semicircle of legislators, with a row of advisers and his wife Wendi Deng behind him, the grim-faced media baron looked like he'd rather be anywhere else.
He seemed reluctant and at times uncertain as he was asked whether he knew staff at his News of the World had been hacking the phones of celebrities, politicians and even teenage murder victims.
He answered several questions with a curt "Nope." Did he know about the illegal eavesdropping? No. Was he aware his News International had paid out hundreds of thousands of pounds to hacking victims? No. Why hadn't he fired a disgraced reporter named Neville Thurlbeck? "Never heard of him."
The implicit suggestion was that the emperor of News Corp. couldn't be expected to know about a newspaper that made up just 1 percent of his globe-spanning empire.
London business consultant Allyson Stewart-Allen said the responses implied "not a lot of knowledge" about fundamental facets of the business.
"The impression is not owning the problem," she said.
In contrast, James Murdoch appeared more conciliatory, repeatedly offering to interject and asking "may I help?" as his father made a finger-wagging point.
University of Glasgow psychologist Patrick O'Donnell said James Murdoch gave a careful, lawyerly performance, "a little bit stressed, a bit evasive."
And despite the younger Murdoch's best efforts, the lawmakers seemed more interested in quizzing his father, who, as Labour lawmaker Tom Watson pointed out, "is responsible for corporate governance and serious wrongdoing has been brought about in the company."
And as the session, slated to last an hour, stretched past two and then toward three, Rupert Murdoch got into his stride.
He grew in confidence; the power balance shifted. While at first the elder Murdoch had turned to his son to amplify his answers, he later seemed quicker to grasp the thrust of questioning.
When James Murdoch seemed to struggle to understand a question about whether News Corp. had been guilty of "willful blindness," his father quickly stepped in _ "We were not ever guilty of that."
Judi James, a body language and behavior analyst, said the father and son ultimately made an effective team.
"They took these two extreme roles," she said. "James is the scrubbed-up PR face of the business," while Rupert played the "curmudgeonly father act."
"Prior to the custard pie, the tension had relaxed in the room and it no longer felt like a witch hunt," she said.
Then came the extraordinary moment when a protester approached Rupert Murdoch with the foam pie he'd managed to smuggle in. Some of the white goo ended up on Murdoch, but more landed in the attacker's face thanks to the split-second timing of Rupert's wife, Wendi Deng.
She struck back at the attacker in a flash. By the time the man had been bundled away, Rupert Murdoch was still seated and James had sprung up but remained shocked and immobile.
When the session resumed after a brief break, Rupert Murdoch _ now in shirt sleeves, his soiled jacket removed _ looked like a man in control. He seemed to know the worst was over. He even showed a hint of emotion as he paid tribute to his father, founder of the Murdoch media empire, "who was not rich but was a great journalist."
The elder Murdoch finished by reading out a statement stressing "how completely and deeply sorry I am."
London media analyst Claire Enders said the Murdochs had appeared to be "on top of most questions."
"They came across pretty well," she said. "Overall, it was a good performance by the Murdoch family."
Shareholders also appeared satisfied. News Corp. shares, which as of Tuesday morning had fallen by 17 percent since the scandal broke, rose 82 cents, or 5.5 percent, to close at $15.79 in New York.
The members of the committee, among them firm foes of Murdoch's media dominance like Watson, appeared impressed _ though they were even more impressed with Deng.
"Your wife," Watson told Murdoch, "has a really good left hook."
AP writers Raphael G. Satter and Christopher Torchia contributed to this report.