While many Americans tuned in to the first game of the Baseball World Series Tuesday, U.S. President Barack Obama had another sport in his sights. Obama made an unexpected appearance at the Chicago Bulls season opener during a two-day trip to his home town. The Bulls tipped off against LeBron James's fancied Cleveland Cavaliers. Obama arrived to cheers toward the end of the first quarter, ditching his tie and jacket, rolling up his sleeves and slapping hands with fellow spectators as he took his seat.During the first intermission he was entertained by Benny the Bull, a dancing mascot, and he chatted with longtime friend Marty Nesbitt. He received loud cheers a little while later when, during a break in play a ball rolled toward him and he bounced it back across the other side of the court. For much of the opening proceedings Obama was able to watch the Bulls lead against a team that was 53-29 last season. The Bulls' new coach, Fred Hoiberg, faces a challenge from early season injuries, with Derrick Rose on the mend from a broken orbital bone and Mike Dunleavy sidelined after back surgery. At half time Obama posed for some photos with fans.