What started as a classic showdown between Baltimore's Kevin Gausman and Oakland's Trevor Cahill ended after the A's Jed Lowrie lined a one-out single off Baltimore's third pitcher, Pedro Araujo (1-3), in the 12th.

Orioles pitchers had retired 19 consecutive batters before Lowrie's hit.

Davis worked the count to 3-0, took a strike, and then unloaded with his ninth home run of the season to left field, giving the A's their third walk-off win of the season.

Oakland improved to 3-0 in extra innings, while the Orioles fell to 1-3.

Chris Hatcher (3-0), Oakland's fifth pitcher, was credited with the win after retiring two of the three men he faced in the top of the 12th.

Gausman worked a full nine innings for the first time in his career, allowing just two hits. He walked two and struck out six. He was pulled after throwing 113 pitches.

Cahill likewise was not rewarded for his second straight outstanding home start of the season. He shut out the Orioles for six innings, striking out a career-high 12. He allowed just four hits and a walk.

Cahill's previous high for strikeouts was 10, done twice, once for the A's in 2010 and later for the Arizona Diamondbacks in 2013.

Cahill, who returned to the A's this season after he was dealt away in 2012, has struck out 20 in two home starts this year. He has yet to allow a run in the Coliseum.

Yusmeiro Petit and Santiago Casilla followed Cahill and threw two shutout innings apiece before Daniel Coulombe struck out four of the five batters he faced bridging the 11th and 12th innings.

A's pitchers combined to strike out 20 batters while allowing seven hits.

Mark Trumbo and Anthony Santander had two hits apiece for the Orioles, who lost their fifth straight on a six-game trip that ends Sunday.

Baltimore has lost 11 straight on the road.

--Field Level Media