The Orioles (87-51) earned their fourth straight win, including their second straight to open the current three-game series. Baltimore kept its lead in the American League East at 3 1/2 games over the Tampa Bay Rays, who beat the Boston Red Sox 8-6 in 11 innings earlier on Tuesday.
The winning run came in the top of the 10th when automatic runner Austin Hays came around on back-to-back groundouts against Jose Soriano (0-2), the second one a grounder to shortstop by Jordan Westburg that made it 5-4.
Randal Grichuk, the Angels' automatic runner, was stranded at third in the bottom of the 10th when Shintaro Fujinami got a flyout before striking out Trey Cabbage and Schanuel to notch his second career save.
Joey Krehbiel (1-0) got the win in relief.
With Los Angeles ahead 3-2, Baltimore's Adam Frazier hit a one-out popup off Los Angeles closer Carlos Estevez that fell between three Angels fielders for a bloop double along the left field line. Ryan O'Hearn then tied the game with a line single to left.
After a walk, Mountcastle delivered a single to drive in O'Hearn, and the Orioles led 4-3.
In the bottom of the ninth, the Angels (64-75) tied it against Orioles lefty DL Hall. With one out, Rengifo doubled off the wall in center. Hall got Moustakas to pop out but walked Logan O'Hoppe before Moniak singled up the middle on 1-2 count to tie it.
Both starting pitchers got no-decisions. Orioles right-hander Dean Kremer gave up four hits in 4 2/3 scoreless innings. He struck out five and walked three.
Reid Detmers worked 6 2/3 innings for the Angels, giving up two runs on nine hits and one walk while striking out five.
The Angels were without star Shohei Ohtani, who missed his second straight game due to right oblique tightness.
—Field Level Media