Hayes, is accused of sexually assaulting and strangling Hawke-Petit. Komisarjevsky, who is awaiting trial, is charged with sexually assaulting Michaela.
The July 2007 ordeal began, authorities said, as Komisarjevsky followed Hawke-Petit and her two daughters from a grocery store. Hours later, the two allegedly tied Michaela and Hayley to their beds, poured gasoline on and around them and set the house on fire, killing them and their mother.
After describing a pleasant Sunday leading up to the killings, Dr. Petit testified Tuesday that he was beaten in his sleep and woke up around 3 a.m. face-to-face with Hayes and Komisarjevsky.
"I remember I awoke in a daze thinking or feeling ow, ow, ow," he testified. "Something warm was running down the front of my face. ... I saw two people standing in front of the sofa. ... [A] person who was walking said if he moves put two bullets in him."
Petit said the men bound his wrists and ankles with rope and plastic ties, and covered his face, then took him down to the basement, where they tied him to a pole. He said he went in and out of consciousness. Upstairs were Hawke-Petit and the couple's two daughters.
"I heard moaning and thumps. I may have yelled out, 'Hey!' Then he said he heard someone upstairs say, 'You are alright, don't worry it's going to be all over in a couple minutes.' It was a different tone, it was much more sinister," he testified.
Petit said he did not know the fate of his wife and daughters, but said he heard his wife in the kitchen tell one of the attackers she needed to change clothes and get a checkbook.
It could have cost Dr. Petit his entire family -- though he ultimately managed to escape by untying himself and running to his neighbors.
"I felt a major jolt of adrenaline and thought it's now or never. In my mind, at that moment, I thought they were going to shoot all of us," he testified Tuesday.
He managed to free his hands and hop up the stairs, falling at least once, then finally made his way out the door, he testified.
"My heart felt like it was beating 200 beats per minute," he said, "like it was going to explode out of my chest."
Somehow, he crawled, then rolled to a neighbor's house. Doctors said later Petit had lost as much as seven pints of blood. He said his neighbor didn't even recognize him at first, because he was so bloody.
The neighbor called 911. But it was too late for his wife and daughters.
Hayes and Komisarjevsky allegedly fled the burning home in the family's car and were caught after ramming several police cruisers, authorities said.
In opening statements Monday, Ullmann said Hayes told police that things "got out of control," and that Hayes' co-defendant Komisarjevsky said no one was supposed to get hurt, the AP reported.
"It has been a very painful process to get to this day," Johanna Petit Chapman, Dr. Petit's sister, said outside court on Monday. "And although the pain will never end, we think of Jennifer, Hayley and Michaela every second of every day."
The latest delay is not the first caused by a medical crisis. Hayes' trial was delayed significantly after he was put into a medically induced coma following a suicide attempt earlier this year.
ABC News' David Muir, Sarah Netter and Lee Kamlet, and The Associated Press contributed to this report.