A man accused of murdering a fellow resident at a homeless charity property told a jury he had tried to perform first aid after finding him unconscious.
Sean Keena said it was "like a horror" film as the tried to revive Mark Long and summon medical help.
Keena, 39, is accused of murdering 45-year-old Mr Long at The Saviour Trust property, in South Baileygate, Pontefract, on August 23 last year.
The prosecution claims Mr Long was subjected to a "prolonged and vicious" beating, during which Keena stamped on him at least twice.
Jurors have been told how it appeared Mr Long tried to crawl up the stairs to escape harm during the “death struggle”, only to be dragged back down and eventually lose consciousness.
Keena told the jury of four men and eight women at Leeds Crown Court that he came out of his room and saw Mr Long unconscious at the bottom of the stairs covered in blood.
He said: "I tried to revive him, I pushed down on his ribs. I was doing it very hard. I thought I had broken his ribs."
Defence barrister Nawaz Hussain asked Keena: "Can you remember how long you did that for?"
Keena replied: "A couple of minutes." He added: "I needed to get some proper medical help but it was hard."
The defendant said he was unable to find a phone then ran outside in his underwear and tried to stop passing cars.
He said: "It was like it was a horror film."
Asked if he attacked Mr Long in any way, Keena replied: "No. I swear down. I would never do that."
Long distance lorry driver Adrian Spurgeon found Mr Long laid in the blood stained hallway of the four-bedroom house.
There were no signs of life and Mr Long was pronounced dead at the scene by paramedics.
The court has heard Keena and Mr Long were among four residents at the house, and their regular drunken arguments were so disruptive that a fellow resident had asked to be moved.
The trial continues.