As soon as the ball came off Ryan Braun's bat, Rickie Weeks knew he had to take off.

Waiting at third base, Weeks took off on Braun's grounder and slid, head-first, beating Koyie Hall's tag by inches to give the Brewers a 4-3 victory over the Cubs on Opening Day at Miller Park.

The ninth-inning dash capped an aggressive trip around the bases for Weeks, who tied the game earlier in the inning with a one-out double and advanced to third on a wild pitch. Corey Hart walked, putting runners at first and third, setting the stage for Braun.

With the crowd of 45,455 -- the second-largest in Miller Park history -- on its feet, Braun slapped a 1-2 fastball from Cubs' closer Kevin Gregg to shortstop Ryan Theriot. Theriot wasted little time getting off the throw on Braun's come-backer and though it looked from a distance as if Weeks was out, home plate umpire Jim Reynolds quickly put up the "safe" sign.

"I was safe, but it was a real close play," Weeks said. "The ball got in there at almost the same time that I did. I got my hand in there."

Weeks' baserunning got the Brewers on the board in the first inning. He led off the game by reaching second on a fielding error by Theriot. He moved to third on Corey Hart's sacrifice bunt and scored on Braun's single to give the Brewers an early 1-0 lead.

Weeks is batting just .200 (3 for 15) with a pair of doubles, scored three times and driven in a pair. He's drawn just one walk in four games but has been hit twice and has a .333 on-base percentage so far. Baby steps, yes, but it's progress for Weeks, who has drawn the ire of fans over the past few years.

"It just echoed what he did all spring," said Brewers Manager Ken Macha. "It was a great game for Rickie, just a great game."

As valuable as Weeks was on the base paths, he played just as big a role with his glove work. Showing continued improvement as a second baseman, Weeks twice snared shots in the dirt on plays that would have been problematic last year.

In the second, he saved a run by snaring Mike Fontenot's line drive and flipping it to shortstop J.J. Hardy for a double play that was followed by a Ryan Theriot double.

"I've just stayed confident like I've always been," Weeks said. You can't worry about the past, you can only work on the future. That's what I'm doing right now."

Weeks' play help cover up for an offense that had been lackluster at best against Chicago starter Rich Harden. Milwaukee stranded 10 runners and went 1 for 6 with runners in scoring position.

Save for Corey Hart's third-inning home run and Weeks' efforts, the Brewers did little with the three other hits and seven walks they got off Harden. The right-hander, who played for Macha in Oakland, was on his game, issuing 10 strikeouts.

But for Macha, the walks were a sign that his team was finding its groove after a rough start to the season in San Francisco. Especially in the ninth inning, a spot that the Brewers have struggled with in the past.

"We had a lot of discipline at the plate," Macha said. "(Chris) Duffy reached on a walk in the ninth. Corey with two strikes in the ninth showed some discipline and drew a walk and that got Braun up there with the winning run at third."

Brewers starter Braden Looper -- signed as a free agent last winter -- wasn't sharp in his 2009 debut. He labored through five innings, throwing 97 pitches but allowed just one run on five hits and four walks. He frequently fell behind in the count but was able to work out of jams with his change-up.

"His command was pretty good," Macha said. "He made his pitches when he had to. He's had an abbreviated spring. I thought that was enough for him. He did a great job, getting out of there with one run."

Looper, who missed time during spring training with muscle soreness, wasn't happy with his debut but acknowledged that he's still a little bit behind schedule compared to past seasons.

"I definitely won't say I felt like I pitched my best," Looper said. "I went out there and knew early on that I didn't have command the way I normally do. It's one of those days that, in the past, I've had to learn how to pitch."

The victory ended a long day for the Brewers, who returned to Milwaukee from San Francisco at about 5 a.m. Add in the later start time for the game and all the pomp and circumstance that goes with Opening Day, getting out with a victory was the perfect remedy.

"It feels good," Weeks said. "Coming in at 5 o'clock in the morning, trying to get a couple hours of sleep and get to the ballpark in time then rushing through our routine ... we just tried to press our way through the game."