Oscar Pistorius has dramatically described the seconds before shooting dead his girlfriend Reeva Steenkamp.
The athlete took his prosthetic legs off in court to emphasise his vulnerability as he described grabbing his gun amid fears he was being burgled.
"My lady that's the moment everything changed," he told the court.
Oscar Pistorius arrives at court today
He told the court how he "whispered" to Reeva to call the police as he made his way to the bathroom with his firearm.
The court was adjourned for lunch before Pistorius was able to describe the actual shooting.
During a dramatic morning in court, Pistorius outlined in fine detail his version of events on the evening and night of the shooting on February 13/14 last year.
He began by explaining how Reeva had cooked him dinner and the pair ate about 7pm.
A bucket in the dock in case Pistorius is sick again
After dinner they sat at the dining room table and "chatted about our days".
"Just before 8pm I came into my room and I opened the balcony doors - it was very humid," he told the court.
"I drew the curtains around the fans. They were blackout curtains.
"At that point Reeva came into the room and I took my drink and I put it down on the bedside table.
Aimee Pistorius, Oscar's sister, at the trial today
"I locked the bedroom door and I put the cricket bat about 2cm from the door. I put the cricket bat on the floor so the door would be blocked by the cricket bat.
"I took my prosthetic legs off, so they could air. I put them as close to the door as I could. I climbed onto the bed.
"Reeva jumped on the bed and we were chatting. I was texting my cousin - Reeva was on a social media application. She was showing me pictures of cars and things that she liked."
Pistorius then called his cousin and Reeva got out of bed and started doing yoga at the foot of the bed.
"Every now and then, Reeva would get up and give me a kiss. Reeva then walked to the bathroom.
"She called me to come and brush my teeth. She went back to the bedroom. When I came back she was lying in the middle of the bed."
Pistorius said that he fell asleep between 9 and 10pm.
His voice quaking, Pistorius continued: "I woke up in the early hours of February 14.
"It was extremely warm. I sat up in bed. I noticed that the fans were still running and the door was still open. Reeva was still awake. She rolled over to me and said 'Can't you sleep my baba?'.
"I said 'no I can't, not tonight'."
June Steenkamp sat stony-faced through the evidence yesterday
Pistorius said he then locked the sliding doors of the room.
"I came into the room. The only bit of light was a little LED light. I could see a pair of jeans on the floor. I picked them up and was going to place them over the lights.
"At this point I heard a window open in the bathroom.
"My lady, that's the moment everything changed. I thought there was a burglar gaining entry into my home.
"I think initially I just froze. I heard a noise and In interpreted it as someone climbing into the bathroom.
Oscar Pistorius wept in court yesterday before giving evidence
"I immediately thought someone could be there any moment and the first thing that ran through my mind was that I needed to arm myself, to protect Reeva and I - that I needed to get my gun.
"I ran and grabbed my firearm. When I got before the passage wall, I was scared that the person could have been in a closet space.
"I had my firearm extended in front of me. I whispered to Reeva to get down and phone the police."
He continued: "I was overcome by fear. I screamed at the person to get out. I screamed at Reeva. I was constantly aware this person could come at me at any time. I did not have my legs on. Just before I got to the bathroom, I stopped shouting."
At this point, the court was adjourned for five minutes for Pistorius to remove his prosthetic legs and demonstrate the difficulty he had moving without them.
Pistorius said meeting Reeva Steenkamp was a 'blessing'
He then continued, just before the case was adjourned for lunch: "I heard the toilet door slam. It confirmed there was someone inside the bathroom at that time."
Earlier in his evidence, Pistorius said he had bought Reeva a bracelet from a designer that she liked for Valentine's Day, which he planned to give her.
He said that Reeva had wrapped a present for him on the evening of the shooting but he was told he was only allowed to open it the following day.
"On August 8 last year, on Reeva's birthday, I opened it, it was a photo frame, with four photos of her and I and the card that she wrote....," he sobbed.
Pistorius was too upset to continue with the description.
The court is sitting for its 18th day in the trial
Earlier, the 27-year-old was "dripping with tears" as he gave evidence for the second time at his murder trial in Pretoria, South Africa.
He described the start of their relationship and read out a series of instant messaging texts, detailing its ups and downs.
During another emotional morning in court, he also denied details relating to firearms charges against him.
In one of the texts read out in court by Pistorius, Reeva denies being a "flirt" and in another she denies being a "stripper and a ho".
Reeva also sent Pistorius a message saying: "I'm scared of you sometimes and how you snap at me and how you will act towards me."
In a reply to Reeva, Pistorius admitted to feeling "jealous and insecure".
Describing a fight at an engagement party he told the court: "I just think it was a bad hour in our relationship."
Reeva's mother June attended the hearing along with Reeva's friend Gina Myers, who was wearing tags that bore a black-and-white print of the model.
The athlete's voice faltered as he read a series of loving messages where they traded affectionate pet names.
The pet names included "amazballs", "baba", "boo", "angel" and "babycakes".
One text from Reeva to Pistorius read: "I only have eyes for you." In another she wrote: "I want to kiss you and feel your arms around my neck."
He also described buying Reeva flowers and chocolates.
Describing the start of their relationship Pistorius told the court how they began dating at a sports award ceremony.
He said: "I really didn't think that she would go with me (...) I phoned her and she said she would go with me.
"After the evening we sat speaking until 2 or 3 in the morning. She was a fantastic date."
Pistorius said he believed that he was "more into" Reeva than she was into him.
"I was very keen on Reeva. I was besotted with her," he said.
Pistorius also explained how Reeva was subjected to a "hate campaign" after she began dating him, including people who set up fake social media accounts.
"She had her own stress, on top of what I had to deal with," Pistorius told the court.
Speaking from the court Sky's Alex Crawford said: "Often he's literally dripping with tears, he's using his handkerchief to mop his tears.
"Reeva's mother June has been staring steadfastly ahead."
Pistorius is expected to field questions all day and describe events relating to the death of his girlfriend.
Pistorius shot Reeva, 29, dead in the bathroom of his home but denies murder, claiming that he thought the model was an intruder.
He also denies illegally possessing ammunition and two further counts related to shooting a gun in public in separate incidents prior to the killing.
Yesterday, Pistorius slumped on the floor of the dock after testifying for most of the day, unable to continue because he was too exhausted.
He wept and trembled his way through his first day of defence evidence, describing how panic attacks had left him hiding in cupboards since the shooting.
He told the court he woke "smelling blood", was unable to sleep and was on anti-depressants and sedatives.
And in dramatic scenes in Pretoria, the day ended early with Pistorius sitting on the floor of the dock with his psychologist wiping away tears and stroking his face.
The athlete's family formed a protective shield around him as he composed himself before eventually leaving the building.
Moments earlier, the court hearing had been adjourned for the day after Judge Thokozile Masipa agreed that Pistorius was "exhausted", having not slept.
Yesterday morning, Pistorius cried as he turned towards Reeva's mother June and apologised for all the hurt he had caused her.
His voice cracking, he said: "I would like to take this opportunity to apologise to Reeva's family, to those of you who knew her who are here today, to her friends.
"There hasn't been a moment since this tragedy happened that I haven't thought about your family."