The Rangers had entered the series having just outscored the Mariners, 31-6, in their last three games, but Narveson was impressive in shutting them down.
"It's just knowing what type of pitcher you are," Narveson said. "Sometimes you get out there and you have this feeling that you have to make pitches that maybe you're not comfortable with or that aren't the right pitch in that situation.
"So to go out there and be able to establish the game early, set a good tone, that was able to get me where I needed to be."
Brewers manager Ken Macha said the key for Narveson was his changeup.
"He made his pitches. The ball was down for the most part all day, and the change was really good," Macha said. "In the first inning, he used the change, and they were swinging and missing at it.
"I've got a friend that lives down in Texas -- he watches all of their games. He called me twice saying, 'These guys are swinging the bats well.' And they did against Seattle. It says something about how Narvy located the ball today."
Although strong Brewers pitching performances lately haven't come with much offense, that was hardly the case Friday. The Brewers' Nos. 2 through 5 hitters each belted a home run, driving in all six of the runs for the club.
Ryan Braun, batting cleanup for the fifth straight game, got the Brewers on the board in the first with a two-run blast to left-center field, his ninth of the season.
After a Casey McGehee solo homer in the fourth, Corey Hart and Prince Fielder went back-to-back in the fifth as the Brewers matched a season high with four home runs on the night.
Hart's home run was his 17th of the season, and his 14th in his last 26 games, dating back to May 15. The Brewers' right fielder added 29 RBIs over the same stretch.
"I'm eating a good diet," Hart said, joking after the game. "I'm not a home run hitter, so I think I'm just getting lucky right now. I'm just trying to make contact, and fortunately for me it's going out. I'm just trying to stay with it as long as I can."
Brewers hitters roughed up Rangers starter Rich Harden, who gave up all six runs on seven hits while walking three and striking out four batters.
Harden (3-3) hasn't faired too well against the Brewers over the last two seasons. In four starts since the beginning of the 2009 season, Harden has given up 20 runs -- 16 earned -- on 23 hits in 17 innings pitched.
His previous starts at Miller Park had been good, however, as he entered with a 1-0 mark and a 1.38 ERA in two starts here.
"They've seen me over the past few years, but I know them pretty good, too," Harden said of the Brewers. "I just didn't make good pitches. I couldn't get the ball down on some hitters, and it cost me."
Narveson's most impressive inning came in the sixth, after he gave up a leadoff double to third baseman Michael Young.
Retiring the next three batters he faced, Narveson stranded Young at third, keeping the score at 6-2.
Along with good hitting, starting pitching and defense, the Brewers got another good performance from the bullpen, as Kameron Loe threw two scoreless innings to close out the ballgame. After putting it all together, the Brewers have won three of their last four.
"That's the trick in this game is to get everything to match up at one time," McGehee said. "Fortunately tonight, we were able to do it."