Former All Black Sione Lauaki has been told that alcohol is clearly his biggest problem and something he needs to think about as he cannot control himself when drinking.

Lauaki, who played the last of his 17 tests for the All Blacks in 2008, appeared in Hamilton District Court yesterday for sentencing after pleading guilty to charges of assault and careless driving.

In March, Lauaki punched twice in the mouth a man he accused of stealing his drink at Hamilton's Coyote Bar.

Yesterday, Judge Philip Connell described the attack as gormless, particularly after the court heard that it was one of his own friends who had taken his drink.

"You had no idea that he was the person who took your drink but you just decided to get angry and take it out on him ... That's the sum total of the stupidity of your actions," he said.

"I think the biggest problem you have got is [that] when you drink, you clearly can't control yourself and it's something you need to think about."

In April, Lauaki hit the headlines again when he fell asleep at the wheel of his 4WD and crashed through a fence and into a paddock 2km south of Huntly on State Highway 1.

He was driving north to visit his family in Auckland after drinking alcohol during a meal that followed his Chiefs side's 25-25 draw with the Cheetahs. He registered 160 micrograms of alcohol per litre of breath; the legal limit is 400mcg.

Yesterday, Judge Connell said: "I'm certain this was at the lower end of the offending scale when it comes to bad driving. But we all have the obligation to make sure we don't fall asleep when we are driving ... The decision was a bad one; you shouldn't have driven."

The judge convicted Lauaki and fined him $800 for the assault and $400 for careless driving.

He also ordered him to pay $500 for emotional harm to the man he punched and $545 to repair the damaged fence, and disqualified him from driving for two months.

Lauaki had little to say when he emerged from the court with his agent, Bruce Sharrock.

"Looking back now it's something silly that happened that night but I'm glad it's over with and dealt with," he said. "I'm just looking forward to heading off to France and restarting my rugby career."

Earlier in proceedings, his lawyer, David Allen, had sought a discharge without conviction saying a conviction would have serious consequences on his future as he had received an offer to play rugby in France.

Yesterday, Mr Allen withdrew the application but pleaded Lauaki's case, saying he had suffered under intense media scrutiny and the loss of a "very significant" rugby contract in Japan that was terminated after news of the assault broke. Lauaki has since signed with Clermont Auvergne but Mr Allen said this contract was "not in the same ballpark financially".

Lauaki is due to join his new club next month.