"You cannot continue playing these games," said Iraq's former president, who had repeatedly interrupted witnesses and the judge. "If you want my neck, you can have it."
Saddam yelled at one of two witnesses: "Don't interrupt me, you boy."
The chief judge adjourned the trial until Wednesday after a highly charged session in which two men became the first witnesses to face Saddam in court.
But Raid al-Juhi, the chief investigative judge, later told reporters that the trial would resume on Tuesday after the prosecution and defence teams asked him to continue for security reasons and because of the advanced age of the witnesses.
During the hearing on Monday, Ahmad Hasan, 38, said he and his family were seized and tortured after a 1982 attempt on Saddam's life in the Shia town of Dujail.
Hasan, who risked reprisals by letting his face appear on television as he gave evidence, said they were taken to an intelligence building in Baghdad run by Barzan Ibrahim al-Tikriti, Saddam's half-brother and former intelligence chief.
Al-Tikriti, one of eight men charged with crimes against humanity, yelled at Hasan: "He should act in the cinema."
"I swear by God, I walked by a room and ... saw a grinder with blood coming out of it and human hair underneath"
Ahmad Hasan, witness
After chaotic procedural wrangling, during which Ramsey Clark, a former US attorney-general, led a defence walkout over threats to the lawyers and a challenge to the legitimacy of the court, Hasan gave his testimony.
"I swear by God, I walked by a room and ... saw a grinder with blood coming out of it and human hair underneath," Hasan told the court.
Al-Tikriti, sitting behind Saddam in the dock, interrupted Hasan, shouting: "It's a lie."
Hasan said: "My brother was given electric shocks while my 77-year-old father watched ... One man was shot in the leg ... Some were crippled because they had arms and legs broken."
Saddam and his co-defendants are charged with killing 148 men from Dujail after the assassination attempt. Other trials over the oppression of Shia and Kurds by Saddam, who is a Sunni Arab, are expected to follow.
The trial began on 19 October but was adjourned for 40 days to give the defence time to prepare, and again last week to let two of the defendants find new lawyers after a second defence lawyer was killed last month.
Saddam Hussein interrupted
witnesses several times
In his testimony, Hasan described seeing al-Tikriti in Dujail on the day of the attack in July 1982, wearing red cowboy boots and blue jeans, and carrying a sniper rifle. He said Saddam was there as well, and related an episode involving a boy of 15.
"Saddam said to him, 'Do you know who I am?'" Hasan said, adding that when the boy answered "Saddam", the president picked up an ashtray and hit him on the head.
As he listened to the testimony, Saddam chuckled and half smiled to himself. Later, his chief lawyer, Khalil al-Dulaimi, argued with the witness and accused him of lying, saying he had implicated a former government minister who had died in 1979.
As the bespectacled Shia prosecutor was asking questions, Saddam's temper flared. "Hey, you in the glasses, don't you recognise your leader of 30 years?" he shouted.
The second witness, Juwaad al-Juwaad, said his 16-year-old brother was detained and executed after the assassination attempt in Dujail.
Al-Dulaimi, for the defence, asked the witness how he could possibly identify anybody when he was only 10 at the time.
Witness Juwaad al-Juwaad
wipes his eye as he testifies
Al-Tikriti stood up and yelled across the courtroom and then hit guards with his notebook as they tried to subdue him.
Up to nine more witnesses are due to testify in the coming days. Most will be hidden behind a screen or will not appear on camera to protect their identities, officials have said.
Hasan's testimony followed a tense few hours when Saddam's defence team stormed out of court, returning 90 minutes later to challenge its legitimacy.
The walkout was lead by Clark, a veteran defender of unpopular high-profile causes, and was joined by Najib al-Nuaimi, a former justice minister of Qatar.
As they left, Saddam shouted that the court was "Made in America" and then: "Long live Iraq!"
Behind him, Barzan chorused: "Long live Saddam." He then said: "Why don't you just execute us and get this over with?"
Al-Tikriti, Saddam's half-brother
was head of Iraqi intelligence
Clark and al-Nuaimi returned after receiving assurances that they would get time to address the court. They then assailed a lack of protection for the defence and impugned the legitimacy of a tribunal originally formed under US occupation.
"This trial can either divide or heal," Clark, who has previously represented former Serbian leader Slobodan Milosevic, told the judge when given five minutes to make his argument.
"An essential element of fairness ... is protection," he said.
"There is virtually no protection for the nine Iraqi lawyers and their families who are heroically here to defend truth and justice."
Rizgar Muhammad Amin, the chief judge, listened and then cut Clark off after five minutes, before granting al-Nuaimi 15 minutes. Al-Nuaimi launched into an indictment of the tribunal, saying it was illegal under international law because it was formed by an occupying force.
"There's no legal basis for what's taking place, this is part and parcel of the legal system in Iraq," he said.
Khalil Dulaimi, defence counsel,
accused a witness of lying
"This land is becoming more American than Arab."
A senior United Nations official told Reuters on Sunday that he doubted that the proceedings could meet international standards.
Saddam and seven of his aides, who have pleaded not guilty, face the death penalty if convicted.
The former president denounced all the charges against him, saying that he was the victim.
"The case has been exaggerated. Every head of state who is subject to an attack has the right to see the assailants brought to justice," he said, referring to the attempt on his life.