BALTIMORE -- Closer Craig Kimbrel blew his second save in as many opportunities and departed with back tightness Sunday as the Oakland Athletics rallied to a 7-6, series-deciding victory over the Baltimore Orioles.

"I mean I don't know how long, what the timetable is with Craig, or if any at all," Orioles manager Brandon Hyde said postgame of the nine-time All-Star. "We'll see. I think we've been playing pretty good baseball, we've just had a couple unfortunate kind of endings this series."

Two nights after he threw only eight of 24 pitches for strikes, Kimbrel (3-1) threw six straight balls to open his outing, the fifth of which prompted the first visit from Hyde and team medical staff.

"The way he was walking around didn't look right," Hyde said of what prompted that talk.

Kimbrel eventually persuaded Hyde to let him continue the at-bat against Kyle McCann, who drove the right-hander's 3-2 offering into the seats next to the out-of-town scoreboard in right-center.

Kimbrel then exited after a second visit that included medical staff. Dillon Tate completed the inning for an Orioles team that is now 2-4 in one-run games.

"Honestly, I think we trust our pitching staff," Baltimore catcher Adley Rutschman said. "There's going to be ups and downs. I don't think anyone's worried."

Information from The Associated Press was used in this report.