The murder trial of South African runner Oscar Pistorius has resumed after a break of several weeks with the defendant's neighbor taking the stand.

Johan Stander testified Monday that he was at the runner's Pretoria house just minutes after the shooting of the athlete's 29-year-old girlfriend, Reeva Steenkamp.

Stander told the court that he received a distressed phone call from Pistorius in the middle of night, saying he had killed his girlfriend thinking she was an intruder.

"I received a phone call from Mr. Pistorius and he said on the call, 'Oom (Uncle) Johan , please, please come to my house, please. I shot Reeva. I thought she was an intruder. Please, please come quick.'''

Stander said Pistorius was torn apart, desperate and praying for Steenkamp to stay alive.

The defense used the testimony to reinforce its argument that the runner shot his girlfriend through a bathroom door in a tragic error of judgement, believing she was an intruder. The prosecution argues that Pistorius intentionally shot Steenkamp after an argument.

Pistorius is known as the "blade runner" for his carbon-fiber prosthetic legs. He has won many Paralympic Games medals and in 2012 was the first double amputee to compete in the Olympics.