Derek Norris stroked Oakland's third homer of the game with a go-ahead three-run shot in the eighth, lifting the Athletics over the Chicago Cubs, 8-7, on Tuesday.
Josh Reddick worked a two-out walk to keep the inning alive and up next was Norris, who crushed an offering from James Russell (1-2) over the left center field wall to erase Oakland's deficit and give it a one-run edge.
Norris then made a strong defensive play from behind the plate in the ninth to turn a double-play. On Grant Balfour's strikeout of Starlin Castro, Norris gunned down Luis Valbuena at second base for the second out.
"I just tried to get rid of it as quick as I could," said Norris. "Fortunately (Eric) Sogard was able to make the tag and we got the double play."
Balfour then got Nate Schierholtz to ground out to notch his 20th save. Dan Otero (1-0) picked up the win with a scoreless eighth.
Josh Donaldson hit a two-run homer and Chris Young added a solo shot for Oakland, which was able to prevail despite starter A.J. Griffin allowing seven runs on 10 hits over 5 2/3 frames.
Welington Castillo had two hits and drove in three runs, while Alfonso Soriano hit a three-run homer for the Cubs, who came in winners in four of their last five games. It was Chicago's first ever regular season visit to Oakland.
Chris Rusin made the start for the Cubs after scheduled starter Scott Feldman was shipped over to Baltimore earlier in the day in a trade which brought pitchers Jake Arrieta and Pedro Strop to Chicago.
Rusin lasted just 3 1/3 innings and put his team in an early 3-0 hole after surrendering a two-run homer to Donaldson in the first and then a solo shot to Young in the following frame. However, Chicago rallied with a five-run fourth.
Its third straight hit to begin the frame came off the bat of Soriano, who clubbed a three-run homer to center field to knot the score at 3-3. Anthony Rizzo then walked, moved to third on a Brian Bogusevic single and scored on a Darwin Barney sac fly to put the Cubs in front.
Bogusevic would advance to second on a wild pitch from Griffin, and Chicago took a 5-3 lead on Castillo's base hit, but the advantage wouldn't last.
Soriano and Castro collided in the bottom of the fourth on a Sogard blooper into left, putting runners at second and third. Coco Crisp then knocked in both runners with a base hit into right for a 5-5 game.
Singles from Dioner Navarro and Bogusevic to start the sixth set the table for Castillo, who drilled a double over the head of Young in center. Although Castillo would eventually get caught in a run down trying to go to third, both Navarro and Bogusevic scored to make it 7-5 Chicago.
The Cubs assigned Arrieta to Triple-A Iowa and along with Rusin, recalled outfielder Dave Sappelt from Iowa ... Chicago fell to 23-6 when scoring at least five runs ... The Cubs played in their 121st different ballpark ... The A's have won 17 of their last 20 home games ... Balfour has converted each of his last 38 save chances dating back to last season. Its the longest active streak in the majors and two shy of Oakland's club record.