Weaver (3-0) took over from there. He allowed just one more run, a groundout by Wieters to score Jones, who had tripled. He finished what he started -- his ninth career complete game and first since last July against the Seattle Mariners.
Weaver allowed just five hits, walked none and struck out five in a 114-pitch effort. His ERA sits at 2.43.
"He is good," Wieters said of Weaver. "He knows how to pitch, he locates and uses all of his off-speed stuff. He was able to cruise through three or four innings before we could even get a hit."
The Angels (6-9) scored one more run, an unearned one, against reliever Luis Ayala in the seventh. It was set up by a Mark Reynolds' throwing error, his third of the season. It was the Orioles' second consecutive three-error night; they have 19 errors this season, tied for the major league lead with the San Francisco Giants.
The loss ruined the Orioles' chances of winning three road series on one trip, a feat they last accomplished in 1998.
And it left Arrieta wondering about what could have been.
"The first four innings were very good, and I was on pace to have a very good outing tonight, the pitch count was down," he said. "So it's just frustrating that when we put up two runs in the fifth and I am not able to have a shutdown inning and extend my outing even further it's frustrating. Not really for myself but for the team. We get two runs off a guy like Weaver we need to do what we can to win the game."