The Cubs added a pitcher but lost some ground in the National League Central Division with the loss. Juan Pierre drove in two runs to help Penny win his 15th game and spoil Steve Trachsel's return to Chicago.
The Milwaukee Brewers beat Houston, 5-3, to close to a half-game in the Central, and the St. Louis Cardinals are one game back. Chicago has 25 games to go.
"I think it'll [come down to] the team that scores the most runs, honestly," Cubs shortstop Ryan Theriot said. "It's whoever steps it up first. We're in the race with two other capable teams, one of which is the world champ. Mentally, you have that in the back of your mind -- they've been there before.
"This is what we all came here for, we embraced the race at the end. Let's see what happens."
Trachsel (0-1) did notch his fifth straight quality start, giving up three runs on seven hits over six innings. He looked right at home at Wrigley Field in the first start in his reunion tour since he was acquired Aug. 31 from the Baltimore Orioles for two Minor Leaguers.
It's been 2,892 days between appearances for Trachsel in a Cubs uniform; his last start for the team was Oct. 3, 1999.
"I pitched here a few times with the Mets," Trachsel said. "It was nice to run out to center field and have the guys out in the bleachers cheering for me after having been on the other side. It's a lot of fun, and they're into every pitch. It's fun to pitch in games like that."
He could use a little help. The Cubs have sputtered offensively of late, and Penny (15-4) didn't help. He entered the game ranked third in the National League in ERA and gave up two runs, seven hits and three walks over seven innings.
"The problem we're having here is that we're not getting hits with men on base. That's a problem. We don't have much speed. I've been thinking, we may go with the speed club and try it that way."
-- Lou Piniella
The key may have been the first inning. Alfonso Soriano and Theriot both singled, but Derrek Lee hit into a double play. Penny walked Aramis Ramirez and Daryle Ward then got Mark DeRosa to fly out.
"Sometimes key at-bats are early," Lee said. "We lead off with two singles, and I've got to do a better job right there. You put pressure on him early, you can make it a rough night for him. But with the double play, he's feeling good again. He's too good of a pitcher. When he feels good, he's going to be good."
Piniella did not send Soriano in the first inning, and the Cubs left fielder has yet to attempt to steal a base since coming off the disabled list with a strained right quad.
"There was thought of it," Piniella said. "Remember, Soriano is the one we're taking care of as far as his leg is concerned. The bottom line is we need to start scoring more runs. It's hard to win with the teams we're playing and putting two or three runs on the board."
Can Soriano run?
"I think my leg is 100 percent," Soriano said. "The problem is in my mind. I don't want to try to do too much. I think my leg is good, but who knows? I've done some moves quickly, and I haven't felt anything. I have it in my mind that I don't want to try too much because I don't want to go back on the [disabled list]. Now, these games are very important."
They are, especially with the Brewers and Cardinals on their heels.
"We're not getting hits with men on base, and that's a problem," Piniella said. "Consequently, what happens is the double plays start to mount up."
Luis Gonzalez hit an RBI single in the Los Angeles fourth, but the Cubs tied the game in their half when Ward and DeRosa each singled, and Ward scored on Jacque Jones' fielder's choice. Ward added an RBI double in the sixth.
Pierre and Matt Kemp each hit RBI singles in the fifth, and Pierre tried to score on the latter hit but was thrown out at home by Soriano. Soriano also nailed Russell Martin at home in the eighth. There's nothing wrong with his arm.
Kevin Hart, called up from Double-A Tennessee on Tuesday, made his Major League debut in the eighth. It was a tough introduction, as Hart entered with the bases loaded and none out. He walked Ramon Martinez on four straight pitches to force in a run, then got pinch-hitter Mark Sweeney looking at strike three. Rafael Furcal flew out to left, and Soriano threw out Martin at home to end the inning.
So, what will Piniella do to shake things up?
"We have a little problem scoring runs the last two games," Soriano said. "He's a very smart manager, and he knows what he has to do. Whatever he'll do will help the team."