The Angels go for a three-game sweep on Sunday behind Joe Saunders, who faces Andy Pettitte.
"It starts with John [Lackey]," said Mark Teixeira, whose sixth-inning homer against Dan Giese was the Angels' elixir. "Lackey did a great job keeping us in the game until our offense came alive."
Solo homers by Garret Anderson and Mike Napoli against reliever Jose Veras rocked the Yankees in the seventh after Giese, a 31-year-old journeyman, had held the Angels to Teixeira's homer through six three-hit innings.
Anderson slammed a Veras fastball to right-center for homer No. 12. With two outs, Napoli, sidelined by shoulder irritation since July 6, smacked his game-tying 13th homer into the left-field seats.
"We play to the end, 'til the game's over," said Anderson, whose hitting streak reached 15 games. "The guy who started for them did a great job. Fortunately for us, he didn't pitch the whole game."
Yankees manager Joe Girardi was hoping to navigate the seventh and eighth innings and hand the ball to legendary closer Mariano Rivera. But the Angels pummeled Veras, Edwar Ramirez (3-1 with the loss) and David Robertson for 11 hits and 10 runs while they were getting six outs.
Ramirez, known for his changeup, served a slider that Guerrero launched to right-center to start the Yankees' demise leading off the eighth.
"I was just trying to cover the plate," Guerrero said of his team-high 21st homer. "It's always good to hit one that way."
Driving the ball the opposite way tells Guerrero he's staying back, not lunging and overstriding.
"Patience," said Juan Rivera, whose two-run double contributed to the eight-run eighth. "We have to stay patient, and good things will happen."
Rivera waited patiently and silently for his opportunity, and now he's seizing it as a weapon in the bottom third of a deep and suddenly deadly batting order.
Sizzling Howie Kendrick was the only Angels regular not to join the hit parade, which reached 14 on the heels of 17 hits in Friday night's 10-5 win. But Kendrick was superb defensively with three critical plays.
Napoli reached base all four times, with a single, walk and hit by pitch, in addition to his tying blast.
Lackey had frustrated the Yankees before Alex Rodriguez homered to left-center in the sixth, No. 26. Three pitches later, Jason Giambi yanked a fastball to right for his 23rd homer.
"My stuff was pretty good, but my location wasn't that great," said Lackey, who struck out Xavier Nady, Derek Jeter and A-Rod, respectively, to leave two runners stranded in the fourth, fifth and seventh innings. "You need to get some strikeouts against a team like this."
Making his third Major League start, Giese allowed only two hits and one runner to reach scoring position through five innings.
An Anaheim native who attended Rubidoux High School in nearby Riverside, Calif., the right-hander threw one fastball too many to Teixeira, whose homer to center was his second as an Angel and No. 22 of the season.
"Sometimes, especially in a day game, it takes a home run to kind of wake guys up," Teixeira said. "It's like, 'OK, this guy can be hit.' It puts a little doubt in the pitcher's mind, too. Hopefully, it kick-started a little bit of the offense."
Lackey was touched for consecutive singles in the seventh by Ivan Rodriguez, Melky Cabrera and Johnny Damon for a run. After Jeter bunted the runners along, Bobby Abreu's grounder turned into an out at home on a strong throw by Kendrick. Lackey fanned A-Rod with his 95th and final delivery.
"Howard [Kendrick] made a great play on contact," said Angels manager Mike Scioscia, who'd gone to the mound before Abreu's at-bat to get Lackey's assurance that he was good to go. "That's a much tougher play from the right side -- and he threw a bullet. That was a key play.
"I really feel what John did to minimize damage gave us a chance to get back in the ballgame."
Kendrick had robbed Abreu with a leaping catch in the first that became a double play and started a double play with a glove flip to Maicer Izturis on a Robinson Cano shot off Scot Shields to end the eighth.
Shields snatched his fifth win in eight decisions when the offense put together seven hits, interrupted by a Cano error. Guerrero singled home a second run in his second at-bat of the inning, giving him the club lead with 67 RBIs -- two more than Torii Hunter and Anderson.
The Angels are averaging 6.67 runs per game and batting .298 since the All-Star break, with Anderson (.400) and Hunter (.385) leading the way. With four homers on Saturday matching their season high, the club has 30 homers in 21 second-half games, winning 16.
Their 73-43 record is the best in both leagues and the best in club history after 116 games. The Halos never have finished a season with the best record in the Majors.
"It's very similar right now to '02," said Lackey, a rookie when the Angels won it all six years ago. "We're as hot as anybody right now. It's definitely a good vibe in the clubhouse. If you can't like this, there's something wrong with you."