For the second straight night, the Orioles gathered at home plate for a water-spraying, hand-slapping celebration -- this time with Venditte giving up the winning run.
Chris Davis hit two home runs, the second a tiebreaking shot with two outs in the bottom of the ninth inning off Venditte, to give the Orioles a 4-3 victory Saturday night.
His second drive ruined Venditte's 0.00 ERA.
"He's a great hitter, so right there you can't give him anything,'' the rookie said. "I gave him enough for him to do what he had to do.''
Venditte, who made his major league debut on June 5, became the first ambidextrous pitcher to play in the majors since Greg Harris in 1995.
Venditte made four appearances before going on the disabled list with a strained right shoulder.
To make room for Otero and Venditte, Oakland optioned right-hander Aaron Brooks to Nashville and designated lefty Brad Mills for assignment.
Mills started for the A's on Friday night, his first appearance in the majors this season.
The Associated Press contributed to this report.
Davis' walk-off home run lifts Orioles
Chris Davis hits two home runs, including the game winner in the ninth inning, to lead the Orioles past the Athletics 4-3.