Jesse Atwood and Khambay Tanpirak were getting along fine at the New Year's Eve drinking party until they began arguing over which of them was tougher.

Before long, Atwood was lying face down in a puddle of blood with seven bullets inside him. And Tanpirak was jailed and later charged with murder, a first-degree felony, for his friend's death.Christopher Orwin testified Monday that the beer drinking began at his White City home, 1064 E. Larkspur Drive, about 9:30 p.m. - just after his father left for work. A small group of mostly underage friends was celebrating the arrival of the new year.

But Tanpirak, 22, of Draper, and Atwood, 20, got into a series of "silly" arguments that changed the tone of the party and eventually led to Atwood's death.

"They made a bet," Orwin told the 3rd District Court jury. "Jesse said he could beat up Chai, Khambay's younger brother, and Khambay said he (Chai) could beat up Jesse."

Tanpirak went to look for his brother. Atwood stayed behind and urged others to place their bets with him. But Tanpirak could not find his brother and came back without him. Atwood was angry he'd returned alone, Orwin said.

"Then they changed the bet between Khambay being tougher than Jesse and Jesse being tougher than Khambay," he explained.

The tauntings escalated until Atwood grabbed a large kitchen knife and tried to stab Tanpirak. Orwin jumped between the two of them and pulled the knife away. But the fights continued outside.

Atwood jumped on Tanpirak's back and got him in a headlock, threatening to break his neck, Orwin testified. Others again pulled them apart and Tanpirak left in his truck. But Tanpirak returned 15 minutes later.

Partygoers kept Atwood inside and Tanpirak outside. "He (Tanpirak) just kept saying, `Go get Jesse.' "

Orwin said he next remembers Tanpirak grabbing a rifle from underneath his truck and aiming it at Atwood. Orwin tried to wrestle it away from him but slipped on the ice.

"He took a couple of steps and started firing and just kept going - bap bap bap," Orwin said. "I heard (Atwood) scream `Awww' like he got hit or something and I looked over and he was on his knees."

More shots were fired and when Orwin looked again, Atwood was lying face down. After calling the police, he returned and noticed a knife by Atwood's left hand. Orwin said he picked up the knife but then tossed it back after Tanpirak told him to return it.

During opening statements, defense attorney Lynn Brown said Tanpirak is not guilty because he was acting in self-defense. "It's not a question of whodunnit. The question is the circumstances surrounding what happened," he said.

Brown told the five-man, three-woman jury that Atwood would have seriously injured or killed Tanpirak - who was then weaponless - if Orwin and others had not intervened and taken away the knife.

"Perhaps he shouldn't have come back, but there was nothing legally prohibiting him," Brown said. "He brought the gun back in the event Jesse Atwood attacked him again with a deadly weapon."

The attorney said his client shot Atwood only after Atwood approached him again with a knife. "A person is entitled to defend themselves with deadly force if they have reason to believe a person is about to cause serious bodily injury to them," he said.

During cross examination, Orwin testified that Atwood pointed a pistol at Tanpirak's head and pulled the trigger during a rabbit hunting trip several months earlier. Although there were bullets in the chamber, it did not fire.

The murder trial is expected to last through Thursday.