BALTIMORE -- The Chris Davis power show continued for another game on Saturday night, but the Oakland A's probably would have rather missed the performance.

Davis hit his second homer of the game, a solo shot off switch pitcher Pat Venditte with two outs in the bottom of the ninth inning, to give the Baltimore Orioles a come-from-behind 4-3 victory over the Oakland A's.

The first baseman finished with two homers and three RBIs, giving him 34 of the former and a major-league-high 88 of the latter. Davis also has belted six homers in the last six games, including three in the first two games of this four-game series.

But the game-winning shot wasn't an easy task, going against the unusual switch pitcher Venditte, whom Davis hadn't really seen before. Venditte (0-1), the left- and right-handed side-winder, came on in the ninth, and Davis was the inning's third batter and got just enough of a look at him to help.

"I had a pretty good scouting report after I saw (right fielder Gerardo) Parra's at-bat," Davis said. "I got a chance to see it. The last pitch I hit was actually a good pitch. I was just trying to put the barrel on it and give myself a chance."

Davis actually reached for a low 2-2 pitch vs. the left-hander and basically golfed it out of the park in right-center. That gave the Orioles their second walk-off homer in the last two nights.

"He's a great hitter, so right there you can't give him anything," Venditte said. "I gave him enough for him to do what he had to do."

Baltimore (59-56) had rallied from a four-run deficit to score the 8-6 walk-off victory Friday. This time, the A's took an early 3-0 lead and the Orioles used two homers to tie it before Davis' walk-off homer.

Left-hander Zach Britton (3-0), tagged with just his second blown save in Friday's game, got the win Saturday thanks to a perfect ninth.

The Orioles moved a half-game behind the Angels for the second wild-card spot, which is why manager Buck Showalter just wants his team to keep pushing forward.

"There's an ebb and flow to it," Showalter said. "You are never as bad as a certain moment in the season; you are never as good as a certain moment. I just want to have the type of people that are going to seek their level, that are capable of it. And I think we have those guys."

Oakland (51-67) has lost five straight games.

The A's started fast, though, needing just three pitches to take a 1-0 lead in the first inning against Baltimore starter Miguel Gonzalez.

Center fielder Billy Burns led off with a triple and scored on the next pitch when first baseman Mark Canha grounded to short.

Oakland added two runs in the third thanks to homers from left fielder Sam Fuld and right fielder Josh Reddick. Fuld led off the inning with a blast to right, and Reddick's shot with two outs sailed over the fence in left-center to put the A's up 3-0.

Davis struck for the Orioles in the fourth, hitting a long two-run homer to right.

The Orioles tied the game at 3-3 on Parra's solo homer in the sixth. That's where it was when Gonzalez left after his seven-inning stint. The right-hander struggled throughout the first five innings, giving up the solo homers to Fuld and Reddick and walking the bases loaded in the fifth.

But Gonzalez then got designated hitter Billy Butler to ground into an inning-ending double play, and the pitcher retired the final seven batters he faced overall.

Oakland starter Chris Bassitt did even better, allowing three runs on five hits in eight innings, with all the runs coming on homers.

"Every game he's pitched, it seems like he's out there deep in games," A's manager Bob Melvin said. "The first couple, just gave up one big hit that ended up beating him. Then (he) got over that to get us through the eighth inning."

NOTES: The Orioles recalled OF Henry Urrutia from Triple-A Norfolk and optioned OF Junior Lake back to the team. Lake was recently acquired from the Chicago Cubs for RHP Tommy Hunter. ... Baltimore C Matt Wieters again was out of the lineup because of a hamstring problem. Manager Buck Showalter still doesn't think it's a situation for the disabled list; but, if Wieters isn't ready to go by Monday, they will look it over again. ... RHP Sonny Gray could start the series finale on Monday, according to Oakland manager Bob Melvin. Gray (back spasms) missed Friday night's start but felt better after a 25-pitch bullpen session Saturday. ... P Pat Venditte (the switch pitcher) was recalled Saturday, along with RHP Dan Otero, from Triple-A Nashville. Venditte was 0-0 in four games with Oakland earlier this season before a strained right shoulder sidelined him for 45 games. He went to Triple-A after being reinstated Aug. 3.