Bases-loaded walks by Juan Rivera and Mike Napoli against Chris Ray in the seventh inning, on the heels of two walks and Torii Hunter's second double of the day, broke a 6-6 tie and gave the Angels their first lead. Kendry Morales' sacrifice fly added a run before Mark Hendrickson quelled the threat.
The Angels trailed the Orioles by 4-0 both Saturday and Sunday, and rallied twice. Not since July 1979, against the Yankees, had an Angels team won back-to-back games it trailed by four or more runs. The win went to Darren Oliver (3-0), with Matt Albers (2-2) absorbing the loss.
"It's not always a good position to be in," Angels manager Mike Scioscia said. "In this series, we were able to bounce back. We had some good at-bats with the bases loaded. Juan Rivera and Mike Napoli had two very good at-bats."
So did Guerrero, tying the game at 5 in the fifth with a two-run blast to left-center against starter Rich Hill.
Guerrero, who takes pride in playing the complete game, made it through his first right-field test of the season without a hitch.
Handling three chances, he unloaded one strong throw that suggested he's fully recovered from the torn pectoral muscle that cost him 35 games on the disabled list.
"Vlad looked strong," Scioscia said. "He was moving well in the outfield, got good jumps. He'll probably be sore tomorrow. He made a couple of throws, showed some arm strength."
The noise from his bat also made a distinctly promising sound. Guerrero had a lot of help.
Hours after learning he'd been selected to his third All-Star Game by his peers, Hunter had a game typical of his season: two doubles, an RBI and run scored and one sensational tumbling catch to help extract his team from a potential uprising in the eighth inning.
After Luke Scott's leadoff single against Oliver, Hunter got a quick break on Melvin Mora's sinking liner to right-center and made a tumbling catch.
Another single by rookie catcher Matt Wieters had Baltimore threatening, but Jason Bulger shut it down, retiring pinch-hitter Ty Wigginton and striking out dangerous Brian Roberts.
"Those are hard games," Roberts said. "If you just get your butt kicked from the beginning, sometimes it's easier to handle. But to feel like you're going to win two games and not do it, that certainly is a little bit more frustrating."
After Guerrero's two-run shot, his fourth of the season, Wieters put the Orioles back in front with his third homer in the sixth. It hastened the departure of Joe Saunders, who lasted 5 1/3 innings and yielded six runs (five earned) on seven hits and three walks.
"My whole issue was commanding the ball today," Saunders said, having walked three while notching two strikeouts. "When you can't throw a first-pitch strike, you are going to get hurt like I did.
"The team picked me up today and this one is on them. They did the job."
After Justin Speier shut down the Orioles in the sixth, Erick Aybar's RBI double against Albers got the Angels even again at 6.
Oliver worked a perfect seventh, picking up the victory, with relief from Bulger, when the Angels worked the Baltimore bullpen for four walks, one intentional to Guerrero, around Hunter's second double.
The Angels needed the juice with Saunders searching for the right stuff. A game-opening homer by Roberts was a foreshadowing for Saunders, a 2008 All-Star who has yielded more homers (20) than any pitcher in the AL.
Roberts delivered again in the third after a fielding error by second baseman Howard Kendrick, smacking a two-run double to right-center, stealing third and scoring on Nick Markakis' single for a 4-0 lead.
Aybar's third-inning single and a walk by Chone Figgins set the table for Bobby Abreu, whose double cashed in two runs. Abreu has 35 RBIs in his past 33 games, leading the AL in that span.
Hunter lashed a two-strike RBI double to left after Abreu's shot to dead center to bring the Angels to within a run of the lead.
Robert Andino's sacrifice fly gave Hill a 5-3 cushion that Guerrero erased with his rocket to left-center after Abreu's walk.
Guerrero, four homers shy of 400 in his illustrious career, has gone deep in back-to-back games for the first time since July 19-20 last season against Boston.