Dwight Howard missed a two-handed dunk on his first shot, and the night never got much better for the Los Angeles Lakers. When Howard and Steve Nash took their places alongside Kobe Bryant and Pau Gasol under the Hollywood spotlight, the Lakers opened a season of enormous expectations with an equally big dud of a performance. Darren Collison scored 17 points, Brandan Wright added 14, and the Dallas Mavericks spoiled the Lakers debuts of Howard and Steve Nash with a 99-91 victory over Los Angeles on Tuesday night.