Rangzaib Akhtar told a jury at Leeds Crown Court he did not want to get caught and ran into a garden area and hid when Kevin Jackson gave chase from outside his home in Halifax.
He said he could hear his friend, Raees Khan, shouting for him to come back and eventually he did.
"When I went back up the hill I seen a guy lying down and Raees was standing a bit above him further up the road."
He said he did not look at the man but ran by and up to the Fiesta car driven by another man, Rashad Zaman, who drove them back to Bradford.
Akhtar told the jury he thought the man on the ground had been knocked out and did not realise it was more serious until he heard Press reports that he had died.
"Had you played any part in that man being injured," asked his counsel, Roger Thomas QC.
"No," replied Akhtar.
Zaman, 21, Akhtar, 20, and Khan, 20, have each denied the murder of Mr Jackson, 31, of Lower Skircoat Green, Halifax, on New Year's Day.
The prosecution claim they attacked Mr Jackson, on December 30, when he tried to stop them stealing his father in law's Toyota RAV4 vehicle. He was stabbed in the head and died in hospital two days later.
All three defendants have admitted trying to steal the RAV4.
Zaman, of Apsley Crescent, Manningham, Bradford, also denies five charges of stealing vehicles and one of attempted burglary.
Akhtar of Salt Street, Manningham, denies one charge of car theft. He has admitted a further theft charge and one of attempted burglary.
Khan, of Priestman Close, Manningham, also denies an attempted burglary.
Akhtar told the jury he was involved in the theft of a Honda car on Christmas Day in Saltaire and in an attempted burglary at a house in Cottingley the following day with the intent of stealing keys to an Audi car.
But he denied taking part in an earlier car theft on December 10 where some documents belonging to him, including a job seeker's allowance book, was found in the glove box.
He said he left the documents when he was given a lift for five minutes in the car by a lad called Imran.
On December 30 Akhtar said he, Zaman and Khan were "just cruising about" and ended up in Halifax where Zaman suggested taking the RAV4.
He said Zaman waited in the Fiesta while Khan got into the vehicle by forcing the door lock with a screwdriver. Akhtar said he was keeping watch nearby and heard a woman shout from a window "Oy, what are you doing."
He told Khan to leave the vehicle and it was then the man appeared from the back of the houses and chased them. Akhtar said he was running in front and turned into a garden area where he hid.
Under cross-examination by Robert Smith QC, prosecuting, Akhtar said the decision was made to take the car for joyriding because they were "bored" at the time. He had seen the man grab Khan but not what followed.
Mr Smith said: "Is the truth that you were present and involved in the attack on Kevin Jackson using your hands and feet while Raees Khan used the screwdriver."
"No," said Akhtar.
"Is it the case that Rashad Zaman left his car and ran down the hill and joined the two of you and was also involved in using violence to Kevin Jackson?" asked Mr Smith.
"No," replied Akhtar.
The hearing continues.