SAN DIEGO -- A 23-year-old man who punched a professional surfer once in the head during a fight in La Jolla, resulting in his death four days later, was sentenced Monday to 20 years to life in state prison.

Seth Cravens was convicted Nov. 18 of second-degree murder in the death of 24-year-old Emery Kauanui.

The defendant was also convicted of four counts of assault, and one count each of battery and making a criminal threat, in connection with violent incidents dating back to 2005 and unrelated to Kauanui's death.

Before handing down the sentence, Judge John Einhorn denied Cravens' bid for a new trial, saying jurors had ample evidence on which to convict the defendant of murder.

Einhorn also denied a defense motion to reduce the conviction to voluntary manslaughter.

The judge noted that the group beating culminated with Cravens throwing a "vicious swing" that connected with Kauanui's head, sending him falling back and causing him to hit his head on the pavement.

Einhorn calling the melee "a continuing, a brutally vicious and totally uncalled for" attack on Kauanui.

"By your violence, you took the life of a human being," Einhorn told Cravens. "It's unforgivable."

Deputy District Attorney Sophia Roach urged the judge to sentence Cravens to the maximum term of 26 years and two months behind bars.

"This is a course of brutal and wanton violence," the prosecutor said, referring to the defendant's attacks on six people besides Kauanui. "Mr. Cravens has been terrorizing his own community for years. Everybody knew it."

A tearful Cindy Kauanui said her son -- who was born on the Hawaiian island of Kauai -- loved everyone he came into contact with.

"It's just an amazing life that he lived," his mother said. "He knew the true meaning of aloha."

If her son could be present at the sentencing, he would have told Cravens that Jesus loves him, Cindy Kauanui said.

"That's true aloha," the mother said.

A short video tribute to Kauanui, which was shown in the courtroom, features a clip of him saying, "Surfing is my passion. Even if I don't make money surfing, I will always surf."

Cravens, dressed in a green jail jumpsuit, apologized before his sentence was handed down.

"I just want to say sorry to Emery's family," the defendant said. "I'm sorry to my own family."

In her closing argument at trial, defense attorney Mary Ellen Attridge told the jury that her client acted in self-defense and was not guilty even of voluntary or involuntary manslaughter.

Attridge said Cravens, who is right-handed, punched Kauanui once with his left hand on May 24, 2007, when the victim got up from a one-on-one fight with Eric House, then screamed at Cravens from five inches away.

The victim's girlfriend, Jennifer Grosso, testified that Kauanui had been losing the fight with House when Cravens walked up and hit him, causing Kauanui to fall and crack his skull on the pavement.

Attridge said Kauanui and House had been kicked out of the nearby La Jolla Brew House bar following a drink-spilling incident, after which Kauanui had threatened to "kick House's ass."

The attorney suggested Kauanui was in a "homicidal state of mind," and therefore Cravens' actions were reasonable under the circumstances.

Attridge also contended that the prosecution failed to prove the fight represented a group beating on Kauanui by House, Cravens, Hank Hendricks, Orlando Osuna and Matthew Yanke.

Attridge said outside court Monday that she would file an appeal by the end of the week. She said Cravens was remorseful and prepared for the worst. She said the sentencing was a "sad day."

"I know Mr. Cravens did not intend to kill Mr. Kauanui," Attridge told reporters.

House, Osuna, Hendricks and Yanke pleaded guilty to lesser charges stemming from Kauanui's death and were sentenced to time in jail.

The defendants were charged with being part of a loosely-knit gang called the Bird Rock Bandits, but Einhorn ruled that not to be the case after a preliminary hearing last May.