CINCINNATI -- On a night when Carlos Zambrano should've been toasting his 100th career win, the Cubs right-hander announced he will retire at the end of his current contract.

In his first start after serving a six-game suspension, Zambrano gave up two hits over 6 2/3 scoreless innings and belted his 18th career home run to notch his 100th victory and power the Cubs to a 2-1 victory over the Cincinnati Reds Friday.

Randy Johnson won his 300th game on Thursday for the San Francisco Giants. Zambrano just turned 28 on Monday, and could reach the goal. But he dismissed it.

"Three hundred? Me?" Zambrano said. "No, I'll be out of here in five years."

How does he know?

"After this contract, I'm done," said Zambrano, who is signed through 2012 with a vesting option for 2013. "I'm serious. I don't want to play. I want to help this team, I want to do everything possible to win with this team, but after five years or four years, or whatever I have left on my contract, I just don't want to play.

"I want to stay home and see my daughters grow up and hang out with my family more," he said. "Do you know how many Mother's Days I spend with my mother? Do you know how many things I've lost in my life?

"It's good to be here, it's good to play baseball -- don't get me wrong," Zambrano said. "But five years, four years, whatever I have left in my contract, I will retire. That's it."

And he wasn't kidding.

This was his third try at his 100th win, and first start since May 27, which ended with Zambrano being ejected after an animated argument with umpire Mark Carlson.

Zambrano (4-2) struck out seven to raise his career total to 1,225 K's and move into sixth on the Cubs' all-time list, passing Bill Hutchison (1,222). Next up, Greg Maddux at 1,305 strikeouts.

The Reds did not muster a hit until Adam Rosales singled with one out in the fifth. Jay Bruce singled with one out in the seventh, but that was it off Zambrano, who has been stingy before. He appeared to be in no-hit form again, striking out the side in the first.

On Friday, Zambrano became the 21st pitcher in franchise history to pick up his 100th win, and the fourth to do so in the last 50 years. Fergie Jenkins, Rick Reuschel and Maddux are the only other Cubs hurlers to reach the century mark with the team in that span.

"I feel proud to be in this organization and this situation to win 100 games," Zambrano said. "It's an honor to be here with the Cubs and contribute, especially after what happend my last start. I was disappointed and really down after what happened. Today, I was happy for myself and for the team, also."

Zambrano has won 95 of his 100 wins since the start of the 2003 season, which ranks fourth among all big league pitchers in that span. Johan Santana began Friday with 105 wins, Roy Halladay had 103 and Roy Oswalt 98 since 2003.

"The last two games he's pitched, both have been excellent," Cubs manager Lou Piniella said. "We wanted to get him through the seventh [inning] and he walked the eighth hitter on four pitches."

Angel Guzman got the last out in the seventh, and the Cubs survived a shaky eighth and ninth for the win.

The Cubs loaded the bases in the first on a single and two walks, and Micah Owings (3-7) struck out Micah Hoffpauir but walked Mike Fontenot to force in a run.

Zambrano made it 2-0 with his second homer this season and 18th of his career, launching the first pitch from Owings leading off the fifth. He batted right-handed against the right-hander Owings. A switch-hitter, Zambrano said he felt some discomfort in his left hand during batting practice.

"It's nothing to worry about," Zambrano said.

It didn't appear to bother him as the ball sailed 408 feet to straightaway center.

"I have a pretty decent swing left-handed and right-handed," he said. "I had a little discomfort batting left-handed, so that's why I moved to right-handed."

"Pretty impressive," Piniella said. "Congratulations to Carlos. He should have a little champagne for the guys."