PITTSBURGH – Perhaps the Chicago Cubs should stop worrying about the Brewers and Cardinals, the teams they’re competing with in the NL Central, and become more concerned with the clubs well below them in the standings.

Freddy Sanchez’s bases-loaded triple highlighted Pittsburgh’s six-run second inning and rookie Nyjer Morgan made an exceptional catch and drove in two runs, allowing the Pirates to knock the Cubs out of the division lead with a 10-5 victory Sunday.

Sanchez, one of the majors’ hottest hitters the last six weeks, had four RBIs as the Cubs’ fifth loss in seven games and Milwaukee’s 10-5 victory in Cincinnati put the Brewers back into the NL Central lead. Chicago had owned or shared first place since Aug. 17.

“Look, this loss here isn’t life or death,” manager Lou Piniella said. “We’re behind, I understand. One game in the standings? If we play well enough, we’ll have a chance to get back on top. If we don’t, it’s not going to matter.”

Still, there was a sense of disappointment among the Cubs that they won only once in three games against Pittsburgh, which is two losses away from a 15th consecutive losing season.

“Our goal is to win series. We didn’t win this series, so you turn the page,” Derrek Lee said. “Every game is urgent right now, it’s that time of the year. Every game is huge. … We need to do a better job of winning series.”

Chicago got off to a promising start, taking a 2-0 lead in the second on Jason Kendall’s two-run single up the middle against Matt Morris (9-9), who had won only once in 15 starts since June 17.

But Chicago starter Steve Trachsel (0-2) lasted only two innings – he is 1-6 since June 13 with the Cubs and Orioles – as the Pirates came back with the pivotal six-run inning keyed by doubles from Adam LaRoche and Jack Wilson and Sanchez’s three-run triple. Morgan and Steve Pearce, both of whom made their major league debuts this month, also had run-scoring singles.

“Let’s not get too down about this loss. You’ve still got 20 games to do something,” Piniella said.

Sanchez tried to stretch his triple into an inside-the-park homer in the second but was thrown out at the plate on shortstop Ryan Theriot’s relay throw. Sanchez added a run-scoring grounder during a three-run ninth keyed by pinch-hitter Jose Castillo’s two-run double against Kerry Wood.

The Cubs tried to get back into it on Alfonso Soriano’s 24th homer and fourth in four games, a two-run shot off Morris, and Geovany Soto’s pinch-hit homer in the seventh. But Piniella was forced to use eight pitchers during a tiring stretch in which the Cubs don’t have a day off from Aug. 27 through Sept. 20.

The Cubs were supposed to be off Monday, but will return to Chicago to play a makeup game against St. Louis before going back on the road Tuesday.

“We’ve been playing .500 roughly for a month, or a little below,” Piniella said. “Sooner or later we’ve got to do a little better than that.”