BALTIMORE -- Just like last year, the Ravens have rolled out to a 4-1 start. But let's make it clear: This Baltimore team isn't like the one last year.

The 2011 Ravens are aggressive. They're fearless. And, as linebacker Ray Lewis puts it, they're ticked off.

Baltimore's 29-14 victory over the Houston Texans is further evidence that the Ravens have found that second-half knockout blow. The Ravens just don't beat teams this year. They finish them.

Joe Flacco was in attack mode, constantly looking to hit the deep throw. Ray Rice broke tackles and made the Texans look tired. And the defense dug in for the fourth quarter, shutting out Houston for the final 22 1/2 minutes.

"To have to come out and really win the fourth quarter in that kind of fashion is a huge statement," Baltimore coach John Harbaugh said.

The Ravens have done this all season, outscoring teams 26-6 in the fourth quarter. It's a major turnaround from last year, when that was the soft spot for Harbaugh's team.

A year ago, Baltimore surrendered nine leads in the fourth quarter, including three that were double-digit ones. The Ravens allowed 119 points in the final quarter last season, the second-most in team history.

The reason why the Ravens struggled to finish off teams in 2010 was their conservative style. The offense went into a shut-down mode, and the defense went into a prevent one.

No one can describe the Ravens as going into cruise control. After Baltimore fell behind 14-13 midway through the third quarter, Flacco found rookie Torrey Smith for passes of 19 and 51 yards on back-to-back plays. That led to a Billy Cundiff 25-yard field goal, putting the Ravens back up 16-14.

The Ravens could've played it safe after turning the ball over twice already (Flacco had a fumble and interception), but they didn't. The next time the offense got onto the field, Flacco's first pass was a perfectly thrown 56-yard pass that went beyond the reach of cornerback Johnathan Joseph and into the hands of Anquan Boldin. That turned into another field goal as the Ravens extended the margin to 19-14 early in the fourth quarter.

None of the Ravens would say it, but Baltimore didn't take those shots last year. It wasn't easy to call them in this game, either. Flacco took some staggering hits and the deep throws only exposed him more. He had to look at the stadium's video screen to see if he completed the long pass to Boldin because the Texans had dropped him to the ground.

Still, there's no reward without a little risk, right?

"We're not trying to hang on to win games," Flacco said. "We're going after it. We're saying: 'This is how we're going to win football games.' We're going to continue to attack teams and try to put points on the board to make it not a close game. I think at times, we can rely on our defense a little bit and try to let them close out games. I think the main thing to do in this league is put teams away when you can. That has to be done offensively. So, that's where our mindset is."

The change in the way the Ravens finish games comes from the fact that the Ravens are willing to change.

On the final play of the third quarter, Rice was stopped for a 5-yard loss on first-and-goal from the 10-yard line. Rice went to running backs coach Wilbert Montgomery and asked to switch the outside runs to more inside ones. They both talked to offensive coordinator Cam Cameron, who altered the running strategy in the fourth quarter.

After managing 39 yards through the first three quarters, Rice produced 62 yards in the last one on eight carries (7.8 yards per attempt). His 27-yard run in the fourth quarter set up the clinching touchdown.

"There were times when we could have blinked," said Rice, who finished with 101 yards rushing and 60 yards receiving. "We are poised, and the difference is you have guys growing up."

In the press conference to introduce Chuck Pagano as defensive coordinator, he was asked what he needed to do to make this a Super Bowl defense. His response was improve during "crunch time."

The Texans moved the ball up and down the field on the Ravens in the first half, converting five of 10 third-down chances. In the second half, when it became "crunch time," Baltimore stopped Houston on five of six third downs.

The Ravens made some subtle changes on their blitzes and coverages when it became apparent that Texans quarterback Matt Schaub was going with quick-hitting passes.

"It was a little frustrating but nobody said things," linebacker Jarret Johnson said. "In my opinion, the quality of a good coordinator is his halftime adjustments. Chuck came in and we narrowed it down. So, Chuck did a good job with our second-half adjustments and it paid off."

How much did it pay off? The Ravens' defense held Houston to 21 total yards on the final three possessions.

Baltimore's drive to put away teams is the result of what happened the last time the Ravens saw the Texans. Last December, the Ravens allowed Houston to score the final 21 points in regulation to send the game into overtime. Baltimore eventually won, but the lesson wasn't lost.

Ray Lewis said the players didn't review the game tape of that game because "it was just a lot of things that we didn't like seeing on film."

Said Lewis: "We took it personal coming out this week."

This wasn't as easy of a victory as many expected. The Texans were without their top two players in wide receiver Andre Johnson and linebacker Mario Williams.

But in some ways, the Ravens enjoyed the sweat. It was the second time they trailed in the second half this season and the first at home.

"This is the kind of game that we needed," Rice said. "We needed to be in a good fight against a good team."

It's these types of games where the Ravens can find their knockout punch.