It was the second blown save this year for Rivera, who had converted 41 consecutive save opportunities at Yankee Stadium since the start of the 2011 Major League Baseball season.
The Orioles, after two straight one-run losses, trailed 1-0 entering the ninth inning when Nick Markakis had a one-out single and Adam Jones followed with a two-run homer off Rivera, who was denied his 30th save of the season.
The only other home run Rivera had allowed this season was to Evan Longoria of the Tampa Bay Rays on April 23.
The New York Mets beat the Milwaukee Brewers 2-1 as starting pitcher Jeremy Hefner allowed one run over seven innings. Hefner has won his past three decisions and has a 1.64 earned run average since June 4.
The Los Angeles Angels won for the 10th time in their past 12 games, beating the Boston Red Sox 3-0 as Mike Trout and Hank Conger hit home runs. Jered Weaver and three Angels relievers combined on the five-hit shutout.
To contact the editor responsible for this story: Michael Sillup at email@example.com