Beginning in the fifth inning, Orioles slugger Chris Davis disappeared down the dugout tunnel to sneak in a few swings inside the batting cages below the seating bowl of Camden Yards, preparing himself in case he was needed in the late innings of Monday night's game against the Chicago White Sox.

The bench hasn't been a familiar place for Davis, but mired in a 7-for-54 slump heading into Monday, that's where the Orioles first baseman found himself in the series opener, watching as his teammates failed to convert numerous scoring opportunities throughout the night.

And when manager Buck Showalter called on Davis to pinch-hit with the Orioles down to their second-to-last out of the game, he washed away all of the club's lost chances with one swing.

Davis crushed a full-count delivery from White Sox closer Ronald Belisario (3-4) deep into the right- field seats for a three-run homer to give the Orioles a 6-4 walk-off win in front of an announced 17,931 at Camden Yards.

“Any time you're able to deliver and come through for your team, it's big,” Davis said. “Like I said earlier today, I'm working as hard as I can to get back on track, doing everything I can and just knowing that as long as I continue to work, the results would be there.”

On a night when the Orioles struggled with runners in scoring position, Davis was patient in the game's final at-bat. After being behind in the count 1-2, Davis took a pair of balls to work a full count before turning on an 82-mph slider.

“It was a nice spot to be in with the game on the line,” Davis said. “Obviously, you want to deliver. When I got down 0-1, to try and shorten up and see the ball up out over the plate and get a good pitch to hit.”

Davis' blast was the Orioles' first pinch-hit, walk-off homer in nearly 26 years, since Larry Sheets hit one against the Seattle Mariners on Aug. 24, 1988.

“It's tough, I'm sure, but he prepared himself for it,” Showalter said of Davis pinch-hitting. “There's no woe is me. He knows at some point the club's going to need a good at-bat from him, and he prepared himself for it from about the fifth inning on."