OAKLAND, Calif. -- The Los Angeles Angels defeated the Oakland A's 5-0 but got a scare Wednesday night.

Angels right-hander Garrett Richards left the game due to right biceps cramping in the bottom of the fifth inning.

Richards blanked the A's on three hits over 4 2/3 innings in his first start since May 1, 2016. He missed the rest of last season because of a partially torn ulnar collateral ligament in his right elbow.

Richards, who opted for stem-cell treatments over Tommy John surgery, threw 76 pitches Wednesday, and according to the Angels, left the game for precautionary reasons. He struck out four and walked one.

"Well, I think with any pitcher when they have to come out of the game, there's a certain amount of concern," Angels manager Mike Scioscia said. "Right now it looks like a cramp in his biceps, not related at all to what he was feeling last year when obviously it was an issue with his elbow. So we're going to take it one step at a time and, as of right now, hopefully he'll make his next start."

Richards said the cramping began on his last five or six pitches of the fifth inning. Catcher Martin Maldonado went to the mound and motioned for Scioscia and a trainer to come out to check on Richards.

"I just told them my biceps was kind of cramping," Richards said. "Elbow and everything felt fine. It was just kind of weird. It kind of feels like somebody punched me in the arm, but nothing crazy. Everything's good."

Kole Calhoun went 3-for-5 and scored a run for the Angels, who beat the A's for the second straight time after losing to them on Opening Day.

Andrelton Simmons finished 2-for-4 with an RBI double and scored a run. Mike Trout went 2-for-5 with an RBI single and a double, his fourth extra-base hit of the series. Danny Espinosa drove in two runs.

"We had some clutch hits," Scioscia said. "We had a lot of opportunities tonight and got five runs."

A's right-hander Jharel Cotton (0-1) allowed five runs on eight hits over 4 1/3 innings. He struck out four and walked two.

"I was leaving the ball up a little bit," Cotton said. "I don't think they were very hard hits. Some broken-bat singles, some flares, but they strung them together really well and got some runs out of it."

Before the fifth inning, Richards was dominant.

"He's a guy, when the velocity's that high, guys were coming back saying the ball's moving all over the place," A's manager Bob Melvin said. "It's cutting, it's sinking. ... The ball's just so unpredictable in what it's doing."

Angels relievers Jose Alvarez, JC Ramirez (1-0) and Yusmeiro Petit combined to blank the A's on three hits over the final 4 1/3 innings.

The Angels grabbed a 3-0 lead in the top of the second inning. C.J. Cron lined a one-out single to center, moved to second on a walk to Cameron Maybin and scored on Simmons' opposite-field double down the right-field line.

Espinosa drove in Maybin and Simmons with a single.

The Angels extended their lead to 5-0 in the fifth.

Yunel Escobar walked with one out, moved to third on Calhoun's hit-and-run single to right and scored on Trout's single to center. Albert Pujols grounded a hit-and-run single, scoring Calhoun and knocking Cotton out of the game.

After the game, Richards underwent strength tests to test his right arm.

"Everything's fine," Richards said. "There's no red flags or anything, just something that flared up, I guess. I was still able to make some pitches in that inning, too, so it wasn't anything serious."

NOTES: A's RHP John Axford was placed on the 10-day disabled list, retroactive to Sunday, with a strained right shoulder. Axford felt tightness in his shoulder after throwing a curveball while warming up in the bullpen Tuesday night. This marks his first stint on the DL in his eight-year career. The A's recalled RHP Jesse Hahn from Triple-A Nashville to take Axford's place. ... Angels backup C Carlos Perez will make his first start of the season Thursday afternoon in the series finale against Oakland. ... A's RHP Chris Bassitt threw to hitters Wednesday for the first time since undergoing Tommy John surgery on May 16.