After court adjourned, Lambdin limped out of the room.
He now faces a maximum sentence of life in prison for the murder of Touch Choun, 41. Had the jury found Lambdin acted under extreme emotional distress he would have received a lesser sentence of up to 15 years.
Lambdin is insulin-dependent diabetic. For him, 15 years could be a life sentence.
Defense attorneys said they fought not for a reduced sentence, but for the jury to see the killing as it was: the erratic act of a desperate man.
The prosecution dismissed that argument.
"Neither of these people were perfect," prosecutor Fred Burmester said in closing arguments. "But because of the defendant's attack on Aug. 17, Touch Choun does not get to come in here to tell you her side of the story."
The verdict came after about six hours of deliberation over two days.
Throughout the trial, which began Tuesday, Lambdin sat silently as his own attorneys called him a killer. He sat silently while the prosecution played for the jury his anguished confession, in which Lambdin recounted, in detail, how he punched, stabbed and bludgeoned Choun to death.
The defense tried to use these claims as evidence of Lambdin's emotional state, but it was not enough to sway the jury.
"How many people have a wife who's a belligerent drunk, a gambler, who's cheating and then drops a bomb and tells you she's pregnant with another man's child?" defense attorney Neal Hamilton said after the trial. "It's hard to expect any jury to understand what this man was going through."
Prosecutors said if the claims were true, Lambdin should have divorced, rather than killed, his wife.
"Angry, insulted, embarrassed, he said, 'She got what she deserved,' " said prosecutor Anna Rossi. "What she deserved may be what the defendant calls it, but in the state of Utah, we call it murder."
No family members of Lambdin or Choun, who has three grown children, attended the trial. Lambdin is scheduled to be sentenced March 4 before 3rd District Judge Vernice Trease.