HOUSTON (AP) — In the Cubs’ first game following Alfonso Soriano’s leg injury, Chicago had another flat night.

After the Cubs stranded the potential winning run at first base in the top of the 10th, Eric Munson hit an RBI single in the bottom half that led the Houston Astros to a 2-1 victory Monday night.

Chicago, which remained one game behind NL Central-leading Milwaukee after the Brewers lost 6-2 to Colorado, threatened in the 10th against Brad Lidge (3-1) when Jason Kendall singled leading off, took second on a sacrifice and advanced on a flyout. Lidge then struck out Cliff Floyd.

Ty Wigginton was walked by Michael Wuertz (2-3) to start the bottom half, and Jason Lane sacrificed. After Eric Bruntlett flied out, Wuertz threw a wild pitch and Munson singled to right.

Ryan Theriot doubled twice for the Cubs, who have lost four of five.

Chicago manager Lou Piniella said before the game that a scan revealed Soriano had torn his right quadriceps while running the bases against the New York Mets in Sunday night at Wrigley Field.

“We think he’ll be out four-to-six weeks,” Piniella said. “We think it will be around Labor Day.”

Wandy Rodriguez struck out a career-high nine for the Astros, who had lost six of their previous nine. Rodriguez gave up one run and four hits in eight innings, and his 121 pitches were a season-high for the Astros. Chad Qualls and Lidge completed the five-hitter.

Cubs starter Rich Hill allowed one run and three hits in seven innings. He has four no decisions since beating San Francisco on July 16.

Carlos Lee put Houston ahead in the fourth with his 24th homer, an opposite-field drive to right.