Oscar Pistorius describes the 'night that changed everything'.

In one of the most shocking days in the Oscar Pistorius trial so far, the athlete broke down howling as he detailed the “night everything changed”.

It was his second day giving evidence in his judge-only trial.

Pistorius has pleaded not guilty to killing Reeva Steenkamp, saying he mistook her for an intruder.

This was the first time the court heard Pistorius describe that night. Previously, the court had heard from pathologist Gert Saayman about the condition of Steenkamp’s body after she was shot in the head, and the text messages between Steenkamp and Pistorius before her death.

He told the court that as it was Valentine’s Day, they had a light dinner together, then went over a new modelling contract she had been given. He says that they then went to bed early. Earlier, Pistorius had detailed their relationship — presenting a picture full of loving messages and genuine affection.

Lisa Davies writes for The Sydney Morning Herald: “It was clear Pistorius wanted the court to see a picture of relationship-bliss. The athlete was a man besotted with his beautiful girlfriend and she was madly in love with the athletic hero.”

In his most recent testimony, he told the court how he woke up in the early hours of the night to find his fans running and the balcony door and curtains still open. His girlfriend had rolled over and said, “Can’t you sleep, my baba?”

As he went to close the curtains he says he heard a noise coming from his bathroom.

He testified that he grabbed his gun from under his bed and whispered to Steenkamp to “get down and phone the police”.

He says he crept down the passage from his bedroom towards the bathroom on his stumps and holding his gun.

With tears running down his face, Pistorius told the court, in a barely audible voice: “That’s the moment that everything changed. I thought there was a burglar trying to gain entry into my home.

I just froze, I didn’t know what to do. There’s no door between the bedroom and the bathroom. I thought that somebody could be there any moment.

My first thought was that I needed to protect myself and Reeva, get my gun.”

He said he moved down the passage, “as quick as I could”, fearful the intruder might come towards him. “At that point, I wanted to put myself between the person that had gained access to my house and Reeva,” he said.

“Just before I got to the passage of the bathroom, I heard a door slam. It could have only been the toilet door. It confirmed that there were people or a person in the toilet at the time.”

The UK Telegraph reports that the court then paused to bring up a picture on the screen requested by his lawyer, Barry Roux, and a photograph of Steenkamp’s body flashed up.

Pistorius collapsed in the witness box, his arms covering his head, and vomited. He was given a green bucket and the court adjourned for lunch.

Writing for The Sydney Morning Herald, Lisa Davies says, “As Oscar Pistorius broke down, howled and sobbed in the witness box of his murder trial on Tuesday, only two people appeared unmoved. One was the mother of his girlfriend and victim, Reeva Steenkamp. The other was the trial judge.”

Pistorius grew increasingly emotional and distraught as he then described the shooting.

Pistorius said he opened fire after hearing a further noise inside the toilet “that I perceived to be someone coming out”.

His testimony said:

I got to the entrance of the bathroom at the end of the passage where I stopped screaming. At this point, I was certain that the intruders were in the bathroom. I had my pistol in my right hand and peered into the bathroom.

I didn’t have much mobility on the tiles. I had my pistol raised to the corner of the entrance of the bathroom.

I noticed that the bathroom window was open. I was with my back against the wall.

I wasn’t sure if the intruders were in the toilet or around the corner at that point.

Then I heard a noise from inside the toilet that I perceived to be someone coming out of the toilet.

Before I knew it, I had fired four shots at the door.

My ears were still ringing. I couldn’t hear anything, so I kept shouting for Reeva to phone the police.

I was still scared to retreat because I wasn’t sure if there was somebody on the ladder or someone in the toilet.

He said he then went back to the bedroom and realised Reeva Steenkamp wasn’t there.

“I didn’t want to believe it could be Reeva inside the toilet. I didn’t know what to do. I kicked the door. I was crying out, I was screaming. I have never screamed like that.”

The Sydney Morning Herald reports that “with that final statement Pistorius lost his composure entirely, putting his head in his hands and wailing like a man defeated. The one-time South African golden boy was distraught and inconsolable.”

Pistorius was taken from the court howling.

The case was adjourned for another day.