Robertson's arm leads Astros' shutout

The postgame trade with Chicago significantly weakens the Pirates.
PITTSBURGH (AP) -- In one night, the Pittsburgh Pirates managed to help two NL Central contenders improve their chances of winning the division.
First, they put up little resistance as Astros rookie left-hander Jeriome Robertson shut them out for 71/3 innings during division-leading Houston's 2-0 victory Tuesday.
Afterward, the Pirates dealt their top run producer, third baseman Aramis Ramirez, and starting center fielder Kenny Lofton to the contending Cubs for strikeout-prone infielder Jose Hernandez and two minor leaguers.
No wonder Pirates manager Lloyd McClendon must have felt like he had lost twice in the same evening without playing a doubleheader.
Not only did his team lose a game, the trade weakens McClendon's everyday lineup and signals the Pirates have all but given up on winning in the short term.
McClendon couldn't explain how his team went down weakly against Robertson (10-3). Robertson and two relievers combined to pitch Houston's fourth shutout of the season.
Morgan Ensberg homered and Robertson, won his ninth straight decision by helping himself with an RBI single.
Houston, the NL Central leader, had lost four straight in Pittsburgh but has won six of seven and 11 of 13 overall. They're winning at even a higher rate when Robertson takes the mound.
"To me, that was the best game he's pitched," manager Jimy Williams said of his rookie left-hander. "He changed speeds well, he threw his breaking ball.
"He just likes to pitch and he believes in himself," Williams said. "Once you have some success, it makes you feel good about yourself."
Effective job
Robertson must have felt pretty good about facing the Pirates, retiring 16 of 17 batters until pinch-hitter Adam Hyzdu singled with one out in the eighth.
Brad Lidge came on to get Kenny Lofton to line into a double play on the only pitch he threw, and Billy Wagner pitched the ninth for his 29th save in 32 chances.
Wagner has converted his last seven save opportunities and has finished each of Houston's last five victories.
"I felt good, and I definitely felt I could have kept going," Robertson said. "I didn't want to come out. But we've been going to the bullpen all year and any one of those guys down there can do the job. With our bullpen, you're confident they can get the job done."
Streaks
Robertson kept his winning streak going and ended Jason Kendall's 23-game hitting streak as the catcher went 0-for-4. Kendall was within four games of matching Jimmy Williams' 104-year-old Pirates record of hitting in 27 consecutive games.
Pirates starter Salomon Torres (5-3) held the Astros to two runs and six hits over six innings in a spot start, but that wasn't enough to keep up with Robertson.
Torres, who started so right-hander Kris Benson could rest his sore right shoulder, got into trouble when Lance Berkman and Richard Hidalgo singled to start the second.
With two outs, Robertson singled with two outs for his second RBI of the season.
"That was very hitterish right there," Ensberg said. "Torres is throwing his sinker 93 mph and he stayed back with the pitch and took the ball the other way, just like we're trying to do."
Ensberg, moved from seventh to second in the batting order, led off the third with his 19th homer.
Notes
The Astros are 13-1 in Robertson's last 14 starts. His winning streak is the longest by an Astros rookie pitcher. In his only previous appearance against the Pirates, he gave up two runs and four hits in 12/3 innings during a May 12 relief appearance in Pittsburgh.
Houston has won 13 of 18.
Houston won the season series 10-6 despite losing five of eight to Pittsburgh this month.