Kemba Walker finally beat LeBron James, and he did it by helping the Boston Celtics send the Los Angeles Lakers to their biggest loss of the season. Walker ended a career-long losing streak against James, scoring 20 points to beat him for the first time in 29 tries and lead the Celtics past the rival Lakers 139-107 on Monday night. "I'm happy I got one at least, before he goes," Walker said with a laugh after the Celtics snapped their three-game losing streak.