Pettitte (10-7) logged his sixth victory since the All-Star break and won his fourth consecutive start, keeping up his standing as one of the game's most reliable second-half pitchers.
Working economically, Pettitte limited the defending AL champions to five hits over eight innings of one-run ball and, with 104 pitches, likely could have pitched the ninth had rookie sensation Joba Chamberlain not needed the work more.
"I try to take extremely good care of myself," Pettitte said. "I try to train awfully hard in Spring Training before I get to the season starting and try to carry it throughout the year. I'd like to think that's the reason why."
"He's so solid," said Joe Torre, who with the win, his 2,041st as a manager, leaped Walter Alston into seventh place on the all-time list. "That's the only way to describe it. I watched this in 1996. The only thing I see different since he's been back is he doesn't mind being 'the guy' out there."
Detroit scored in unorthodox fashion off Pettitte in the third inning, using a bizarre Brandon Inge RBI double that featured a relay throw cut off by Andy Phillips and an unexecuted rundown play between second and third bases that ended with Inge sliding headfirst. With the slide, Inge avoided a tag from third baseman Alex Rodriguez and right fielder Bobby Abreu -- whose task it was to cover second base on such a play -- nowhere to be found.
That lapse aside, Pettitte otherwise stifled Detroit, striking out five while walking one to improve to 4-0 with a 2.25 ERA in the month of August. For his most recent resurgence, Pettitte credited small mechanical tweaks made before his previous start at Cleveland.
"It's something you can't even see on video," Pettitte said. "You've just got to feel it."
Giambi continued to celebrate his return from a left foot injury by posting his first multi-homer game of the season, clubbing a solo home run off Detroit starter Nate Robertson in the fourth inning and reaching reliever Aquilino Lopez for a right-field, upper-deck shot in the eighth, his 10th and 11th homers.
The first homer was part of a five-run attack against Robertson (7-10), who used 109 pitches to get through six innings and allowed 10 hits and two walks, though he struck out seven.
"When I played against him with the A's, he was that guy we knew was going to be tough ... Andy was always that guy, and he's stepped back in that role."
-- Jason Giambi, on Andy Pettitte's resurgence
Citing his freshness, Giambi seemed to be looking forward to further and similar contributions as the Yankees claw toward their possibility of postseason play.
"I'm excited about it," Giambi said. "Whatever Joe needs, I feel great. Hopefully it will bring a little fresh air, because I rested while I was hurt. This team's been grinding it out. I'll do whatever little things he needs."
Abreu and Rodriguez also had run-scoring hits for New York, while scuffling first baseman Phillips snapped out of a 3-for-16 skid by putting up a three-hit night, including a two-run double off Robertson in the sixth that opened a four-run comfort cushion.
Pumping his fist as he took off down the first-base line, Phillips watched his drive zip over a bad route taken by 20-year-old prospect Cameron Maybin, who was promoted from Double-A Erie earlier in the game and had an inauspicious debut in left field, going 0-for-4 with two strikeouts and a rare play on which he was called out for running into a ball hit in front of the plate.
Similar turns of bad luck aren't foreign territory for Phillips, but Friday's success may signal change.
"It's been interesting, the last week and a half," Phillips said. "I've hit some balls well and right at people, and people have made good plays. That's baseball, and it's no fun to have to swallow it. You keep plugging away."
With Chamberlain, the fresh 21-year-old bullpen weapon, having spent the last three games idle, Torre dismissed any possibility of having Pettitte finish off his gem.
Chamberlain did not disappoint in his sixth Major League inning, entering to chants of his name and handling the heart of the Detroit lineup, getting Gary Sheffield -- a power-on-power matchup -- to fly out before allowing a hit to Magglio Ordonez.
"It looks like it pumps him up," Torre said of the fan reaction. "But when you talk to him and look in his eyes, you don't see that excited feeling. It's something more than a 21-year-old."
Chamberlain retired Guillen and struck out Ivan Rodriguez to secure the game, snapping the Yankees' three-game skid and securing New York's first victory over the Tigers since last year's AL Division Series.
"It's great," Chamberlain said. "You can't describe the feeling. There were a lot of people here going crazy. It makes you feel good, and you kind of use that energy to do the best [you can]."