PITTSBURGH -- Paul Maholm is already focused on the 2006 season.
"Right now it's kind of a tryout for me. I'm just trying to state my case to stay here for a long time," said Maholm (2-0), who allowed four hits in his fourth major league start.
"You always hope to do well, but you just want to show you're ready. As well as I'm doing is a huge shock to me."
Jason Bay extended his hitting streak to 10 games with a solo homer in the first inning and added an RBI single in the third, helping the Pirates win for the third time in four games. Bay is 17-for-40 (.425) with five homers and 15 RBI during the streak.
Freddie Sanchez also homered, becoming the first Pittsburgh player to hit a leadoff homer since Tike Redman on Aug. 12, 2003, against St. Louis.
Aaron Harang (10-13) allowed four runs and seven hits in six innings and has lost two of his last three decisions. He struck out five.
Maholm, who struck out the side in the sixth, has pitched into the seventh inning in all four starts. He also pitched eight sharp innings in his major league debut, a 6-0 win at Milwaukee Aug. 30.
"He just dominated the whole game," Pirates interim manager Pete Mackanin said. "He cruised the whole way. He had everything going, and they were off-balance. It was a very impressive performance."
Nate McLouth led off the fifth with a double and beat catcher Javier Valentin's throw to third on Maholm's sacrifice bunt. McLouth scored on Jack Wilson's one-out sacrifice fly to make it 4-0, with Maholm advancing to second. Maholm was thrown out at home after Bay singled to left.
Bay's single drove in Wilson in the third inning after Wilson singled with two outs and stole second base.
"I just didn't throw as well as I have been," Harang said. "I went out there and tried to keep my team in the game and just didn't execute a couple of pitches and paid for it."
Bay's homer in the first inning was his 30th of the season.
"To hit 30 homers in the big leagues in my second year is an accomplishment I'll never forget," Bay said. "The last two weeks I've had opportunities; I'm seeing more pitches, and that definitely helps. Early on, I wasn't getting a lot of pitches to hit."
Maholm pitched out of two early jams.
Edwin Encarnacion walked and advanced to third on Ryan Freel's one-out single in the third, but he was thrown out at home on Felipe Lopez's grounder to third baseman Rob Mackowiak. Maholm then retired Rich Aurilia on a fly ball.
A leadoff single by Adam Dunn and a walk to Austin Kearns gave the Reds two runners in the fourth, but Wily Mo Pena bounced into a double play before Valentin grounded out.
"Honestly, Pittsburgh has three good young pitchers to build with in Maholm, Zach Duke and Oliver Perez," Cincinnati interim manager Jerry Narron said. "Maholm and Zach Duke are definitely big league pitchers, and we all know Perez is."
Ryan Freel had three of the four hits by Cincinnati, which played its second game without first baseman Sean Casey, who sustained a concussion in the first game of a doubleheader Friday.
"One thing is, with Casey out, we can't feel sorry for ourselves," Narron said. "We have to keep battling and grinding."
Ken Griffey Jr. missed his 12th consecutive game with a strained right foot. ... Bay has started all 148 games for the Pirates ... Adam Dunn needs three runs and eight RBI to become the first player in franchise history with 100 walks, runs and RBI twice. Joe Morgan had all three in 1976. ... Freel entered the game with one hit in his last 20 at-bats.