It didn't take much for Jake Arrieta to unravel after he held the Angels to just one hit over the first four innings: A bad pickoff throw, a couple of well-placed hits and suddenly Los Angeles had a five-run inning.

That was all the offensive support Jered Weaver needed en route to his first complete game of the season, a 6-3 victory over the Orioles that included a gamble by Baltimore manager Buck Showalter that worked to perfection.

Arrieta, coming off a no-decision at Toronto in which he tied a career high with 114 pitches over 6 2-3 innings, lasted just 4 1-3 this time and was charged with five runs, six hits and three walks.

The right-hander's only other start against the Angels was on Aug. 5, 2010, when he allowed two earned runs over 7 2-3 innings before the Orioles won 5-4. That was the longest outing in Arrieta's 44 big league starts.

"Jake's one of the best pitchers we have and he has unbelievable stuff," Orioles third baseman Mark Reynolds said. "If he can just harness it and really learn how to pinpoint his stuff, he's going to be really good.

"I think he gets in trouble sometimes when he falls behind in the count and has to throw a fastball. And when it's not located very well, good hitters will make you pay," Reynolds added. "His first couple of starts he was around the plate a lot and throwing his off-speed stuff for strikes. But tonight he fell behind hitters and had to throw fastballs on fastball counts."

Two of the Angels' first 14 batters reached second base, both on errant pickoff throws by Arrieta (1-1) after leadoff singles by Erick Aybar in the first inning and Torii Hunter in the fifth. Hunter advanced to third on a wild pitch and scored on Mark Trumbo's opposite-field single, triggering the pivotal rally.

Aybar tied it 2-all with a bases-loaded RBI single and Bobby Abreu followed with a two-run single, putting the Angels ahead to stay. Kendrys Morales chased Arrieta with a run-scoring single after a walk to Albert Pujols loaded the bases again.

"Everything snowballed on me in the fifth," Arrieta said. "I let a really great outing slip away."

Weaver (3-0) allowed five hits, struck out five and walked none while going the distance for the ninth time in 181 career starts on 114 pitches. Since the beginning of the 2010 season, the All-Star right-hander is 12-0 with a 1.84 ERA in 15 starts before May 1. The last time he lost a game in April was his second start of 2009.

"He's one of the best," Reynolds said. "He locates very well and he's got that deceptive motion. He changes speeds and puts the ball where he wants to."

Facing a lineup with five left-handed batters including the switch-hitting Matt Wieters, Weaver retired his first 12 batters before Adam Jones broke the spell with an infield hit to third base leading off the fifth. Weaver then got behind 3-0 on Wieters, who got the green light from Showalter and drove his fifth homer deep into the right field seats for a 2-0 lead.

"I just wanted to make a good pitch, and I thought it was," Weaver said. "I didn't think he'd be swinging there, 3-0. But sometimes they do, and it worked out for him. He's a power hitter. The ball might have been up a little, and he put it where he should have put it."

Pujols, stuck in the longest season-opening home run drought of his career, was 0 for 3. The three-time NL MVP is batting .262 with only four RBIs in 15 games and 61 at-bats — after averaging 40.5 homers and 120.8 RBIs over his 11 previous big league seasons with St. Louis.

"I definitely feel what he's going through," said Reynolds, who is still looking for his first homer after averaging 37.7 in each of the previous three seasons. "We're pretty good home run hitters, and to not have one that many at-bats in is pretty tough. But once you get that first one, you quit thinking about it and just keep hitting. So I think we're both going to be fine in that aspect."

Notes: The Orioles ended LHP Tsuyoshi Wada's rehab assignment and are sending him back to Baltimore to be examined by team doctors. He has been in the DL since March 28 with an impingement in his elbow, and no timetable has been set as to when he can resume throwing. ... Reynolds struck out in the third, and is 18 away from 1,000. He led the majors in strikeouts three consecutive seasons with the Arizona Diamondbacks before Cincinnati's Drew Stubbs ended his streak last year. ... Jones, the Orioles' cleanup hitter, is batting .179 with runners on base — and .424 with the bases empty. The seventh-year CF is the only player to start in each of the team's first 15 games. ... DH Nick Johnson was 0 for 3 and is hitless in 23 at-bats, the longest drought by any player since the start of the season.