First the Halos climbed out of an early two-run hole against All-Star candidate Rich Harden, who was missing four to seven mph from his typically overpowering fastball.
Then, after Mark Ellis gave the A's the lead again with a two-out homer in the top of the eighth, the Angels tied it up in the bottom of the frame to set the stage for Garret Anderson, who launched a two-out, two-run homer off A's lefty Alan Embree.
And while the Angels might be inconsistent with the bats, they're anything but when it comes to turning late leads into wins.
Francisco Rodriguez worked a perfect ninth for his Major League-leading 33rd save to give the hosts a 5-3 victory to even up the three-game American League West showdown that wraps up on Wednesday afternoon at Angel Stadium.
"We had it all lined up, with our top relievers ready to go," said A's manager Bob Geren, whose club fell to fell 4 1/2 games behind the division-leading Halos. "But they took advantage of a couple of balls out over the middle of the plate, and it just didn't work out for us."
The two biggest pitches left in the fat section of the strike zone were delivered by Embree, who was making his first appearance since Thursday.
On for the bottom of the eighth after rookie righty Brad Ziegler threw two perfect innings behind Harden, Embree made his first mistake when he gave up a leadoff double to Casey Kotchman. After a sacrifice bunt, Vladimir Guerrero tied it up by chopping a single through the left side of Oakland's drawn-in infield.
"I felt like I made the pitch to get him out," Embree said of Guerrero.
Embree made three good pitches to strike out Torii Hunter and set up his fateful confrontation with Anderson, whom he'd held to three hits in 18 career at-bats.
One of those hits had been a homer, though, and Anderson turned Embree's errant fastball into another, deep to right field.
"I missed my spot by a lot," Embree said. "It was supposed to be a fastball away and it was way in. I wanted to go down and away, and it ran right into his swing. He pulled his hands in and got it. He's a great hitter."
"I was looking for a fastball, trying to react to it," Anderson said. "I'm not trying to get outside myself and do too much. I'm not sure exactly where it was, but being able to get down through it and turn on it is a good sign that my bat speed is there. It always feels good when you can contribute like that. The home run makes it like an exclamation point."
The Angels' five-run output qualifies as an outburst for a team that was heavily favored to run away with the AL West this year. They added Hunter to an offense that already looked to be loaded with Anderson, Guerrero, Gary Matthews Jr. and Howie Kendrick, but in their four games prior to Tuesday, they'd scored a total of two runs while batting .153.
The Angels had scored five runs or more only seven times in their past 38 games.
"Any time a good team is scuffling, you hope to time it right [when you face them]," Geren said. "But any team with that many good hitters is eventually going to get its hits."
The A's got to Angels starter Ervin Santana early, scoring a run in each of the first two innings. Ryan Sweeney opened the game with a single, took second on a single by Kurt Suzuki, moved to third on a groundout and scored on a single by Bobby Crosby. An inning later, Ellis led off with a single, stole second base and scored on a two-out single by Sweeney.
If Harden were at his best, that probably would have been plenty. But he wasn't at his best, and the Angels set the stage for his early exit with their game-tying rally in the third. Harden hit Matthews with a pitch to get the rally started, and after a double by Kendrick, Matthews scored on a sacrifice fly by Jeff Mathis.
Kendrick eventually scored on a groundout by Kotchman, who made several tremendous defensive plays at first base, including a diving stop after which he threw from his backside to Santana covering first to end the top of the sixth and save a run.
"Kotchman beat us a little bit with the glove, too," Geren said. "He had a great game."
Harden did not. His truncated evening ended with his most electric moment of the night, striking out Guerrero with runners at first and second with two outs in the fifth, but his final line was pretty ho-hum by his lofty standards: five hits and a walk with five strikeouts. He never topped 93 mph on the radar gun and was far more frequently checking in at 87-89.
"His velocity was definitely down," Geren said. "Definitely."
Harden didn't seem worried, insisting he wasn't hurting and chalking it up as "one of those nights."
"My feel really was awful today," Harden said. "I was fortunate to get through five innings with only two runs. There are just certain days when you feel kind of tied and your arm feels kind of dead. You just feel different on every pitch."
Santana gave up eight hits and walked two while striking out seven, and he didn't factor in the decision, either. Right-hander Scot Shields took over for the eighth inning and retired the first two batters he faced before Ellis slammed his ninth home run of the year into the Angels bullpen to give the A's a lead that they gave right back.
"I definitely felt confident with the lead we got in the eighth," Ellis said. "Alan's been great for us for the past couple years. But you have to give the Angels credit. They put together a couple of great at-bats."
Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.