NEW YORK (AP) -- This one was easy for the surging New York Yankees.
Alex Rodriguez also connected off an ineffective Randy Wolf for the Yankees (38-33), who have won 10 of 13 to move a season-best five games above .500. New York has outscored its opponents 35-6 during the five-game winning streak.
"It definitely feels like we're really starting to put it together," Giambi said.
Including a 13-0 whitewash Sunday at Houston, the Yankees have tossed consecutive shutouts for the first time since May 7-8, 2005, against Oakland.
This gem came in their first game since ace Chien-Ming Wang sustained a foot injury that is expected to keep him sidelined until at least September.
"He's out. Nobody can do anything about it. You can't put any more pressure on yourself," Pettitte said. "With our offense, you don't need to throw eight shutout innings."
Pettitte (7-5) tied a season high with nine strikeouts, improving to 4-0 in his past six starts. He allowed five hits and walked one, passing former pitching coach Ron Guidry for fourth place on the franchise list with his 171st win for the Yankees.
Coincidentally, it was the 30th anniversary of Guidry's 18-strikeout game against the California Angels at Yankee Stadium, a club record.
"He's so loved here," Pettitte said. "It makes me feel good."
Pettitte, who owns a 208-118 career mark, has allowed one run over 15 innings in his past two starts since giving up 10 in a no-decision against Kansas City on June 7.
The Padres brought about 150 extra people in their traveling party, mostly front-office staff and invited guests, so they could visit Yankee Stadium in the storied ballpark's final season.
But San Diego played a messy game in this 1998 World Series rematch, throwing two wild pitches and committing three errors -- two by fill-in second baseman Craig Stansberry.
The Padres also recalled prized prospect Chase Headley from the minors. Headley made an error in left field and finished 2-for-4 as San Diego lost for the fourth time in 12 games and fell to 11-23 on the road.
"When I first got here, I went out and just kind of looked around, went out to the monuments and did that thing and tried to get the awe out of the way," Headley said. "Unfortunately, it really didn't work. Once the game started and the people started filling in and they're chanting up there, it's a little bit different atmosphere. But it's fun. I had a blast. I had a few nerves, but I had a blast."
Rodriguez homered to center leading off the second, his third in three games and No. 531 career. Giambi connected one batter later and added a two-run shot in the fourth after a leadoff walk to Hideki Matsui.
Giambi leads the team with 17 home runs, three more than he hit last season. He has 37 career multihomer games.
The Yankees tacked on three more runs in the fourth off Wolf (5-5), making his first career appearance at Yankee Stadium in his 10th major league season.
The left-hander entered 3-0 with a 1.91 ERA in his past five starts, but lasted only four innings. He was tagged for seven runs -- five earned -- and six hits.
It was the first time Wolf served up three homers in a game since April 29, 2005, with Philadelphia against Florida.
"I was, quite honestly, awful today," he said. "I could count on one hand the number of pitches I actually executed today. The rest were bad."
Jose Veras, Billy Traber and Mariano Rivera (three strikeouts) completed the seven-hitter, New York's fifth shutout this season, which equals last year's total. San Diego was blanked for the fifth time.
The Yankees also won five straight from May 21-25. ... On Wednesday night, Padres ace Jake Peavy makes his second start since coming off the disabled list. ... Ex-Yankee Tony Clark was San Diego's DH. ... Stansberry was a late addition to the lineup after 3B Kevin Kouzmanoff tweaked his back while taking grounders during batting practice. Edgar Gonzalez shifted from second to third. ... Giambi has both of New York's multihomer games this season, the other coming on April 25 at Cleveland. ... The Yankees have homered in 10 straight games. ... New York struck out 14 batters, its most since July 7, 2006, at Tampa Bay. ... Six of Giambi's last 11 homers have come off left-handers. ... The Padres began the night with a major league-best .990 fielding percentage.