Astros go American, beat Rangers in season opener Mon Apr 1, 2013 1:27am EDT (Reuters) - The Houston Astros made their leap to the American League in some style on Sunday, upstaging the Texas Rangers 8-2 to open their new era and the Major League season with the franchise's 4,000th victory. After spending half a century in the National League, the Astros switched to the AL West this year to give baseball an even 15 teams in both leagues. "It's obviously a great feat for the organization being the 4,000th win in franchise history and our first win as an American League team," Houston manager Bo Porter told reporters. I'm happy for those guys in that clubhouse. The change is a fresh start for the Astros, who are coming off consecutive 100-loss seasons but are hoping to redefine the franchise with first year manager Porter, and new uniforms. In front of an excited home crowd at Minute Maid Park, the Astros made the most of their moment in the spotlight as they got their season underway a day ahead of the majority of teams. Starter Bud Norris tossed 5 2/3 solid innings while the offense came alive behind him. Justin Maxwell opened the scoring with a two-run triple in the fourth inning and the Astros added two more runs in the fifth before Texas cut the lead to 4-2 in the top of the sixth. In the bottom of the sixth, however, pinch-hitter Rick Ankiel delivered the game's biggest blow, a three-run home run against reliever Derek Lowe that made it 7-2. Lowe had just entered the game in relief of Matt Harrison, who suffered a tough start after his career-best 2012 season earned him a five-year extension with Texas. Despite nine strikeouts, the left-hander was charged with six runs and the loss. They were a very aggressive team. I knew I was in for a fight," Harrison said. The fight will now be a familiar one as the Rangers and Astros embark on a new divisional, Texas rivalry. The Rangers, too, unveiled a new-look roster without former MVP Josh Hamilton, catcher Mike Napoli and infielder Michael Young. Off-season acquisition Lance Berkman was slotted third in the lineup, the old hitting spot of Hamilton, and he went 2-for-4 with a run scored in his debut.