Few likely would have believed A's manager Bob Melvin when he referred to the Chicago Cubs as a "dangerous" team before Tuesday night's game. Melvin's straight-faced assessment seemed even more misguided on the heels of the Cubs trading pitcher Scott Feldman and former closer Carlos Marmol earlier Tuesday. Who's rolling their eyes now? Certainly not the A's after the Cubs rallied from an early deficit, held a lead late and made the A's work hard for their 8-7 victory in front of 17,273 fans. The A's surged past Texas into first place in the American League West on the strength of a game-deciding home run by Derek Norris in the eighth. This marks the first time the A's held sole possession of the division lead since June 21. They regained first place by winning at home for the 17th time in 20 games and improving to an A.L.-best 27-13 at the Coliseum, while the Rangers fell to Seattle. Feldman was slated to start against the A's in the opener of the three-game series Tuesday. Instead, the Cubs went with left-hander Chris Rusin, which prompted Melvin to go with right-handed hitting Norris as his starting catcher. "They make a trade, throw a lefty instead, we switch the lineup and (Derek's) the hero," first baseman Nate Freiman said. "That was awesome." Freiman could have been referring to Norris' two-out, three-run homer in the eighth or Norris throwing out Luis Valbuena on the back end of a strike-'em-out, throw-'em-out double play in the ninth. Melvin said Norris' penchant for coming up big with the outcome in question is something he and Norris' teammates almost expect. "He does his best work late in games, with runners in scoring position," Melvin said. Norris entered the game batting only .195. However, Melvin and Norris' teammates are bolstered by past results in tense situations.