The Bobcats put up a better fight. After a week resting their legs and watching the playoffs on television, the defending back-to-back NBA champions rejoined the fray on Tuesday at AmericanAirlines Arena, but, like the Heat’s entire first-round series, this opening game of the Eastern Conference Semifinals didn’t offer much drama — just another blowout. After sweeping the Bobcats to begin the playoffs, the Heat ran through the Brooklyn Nets 107-86 to take a 1-0 lead in its best-of-7 series. The Bobcats felt like a tune-up at the time, but Charlotte gave the Heat more trouble in Game 1 than the high-dollar Nets, which were put together at great cost to compete against the Heat in a postseason series. So far, Nets owner Mikhail Prokhorov’s big investment isn’t paying off. He spent $180 million on his roster this season and that team finished the game on Tuesday against the Heat’s garbage-time roster. On the day he was unseated as the league’s back-to-back MVP, LeBron James led a balanced attack for the Heat and finished with 22 points, going 10 of 15 from the field. He had five rebounds and three assists in 37 minutes of work and checked out to a standing ovation with 2:13 left. Of course, most of the fans at AmericanAirlines were standing at that point only to walk out of the arena and beat traffic home.