Cunningham did his part by hitting a go-ahead three-run homer -- the first of his career -- in the eighth inning, leading the way to the A's 7-4 victory over the Rangers at McAfee Coliseum.
In the clubhouse afterward, Cunningham found out the Triple-A Sacramento River Cats had won their game in Oklahoma, earning him a Pacific Coast League championship ring.
The A's rookie has made the best of his opportunity in the Majors, hitting .304 with 10 RBIs in 12 games since being called up. On Sunday, he finally hit that first homer he said was good to get off his chest.
"It's a good feeling to get it out of the way and hit a home run," said Cunningham, who hit 17 homers at Triple-A this season. "Off the bat, I thought it had a chance. Then, I got closer to first base and I thought he [Marlon Byrd] was going to stand there and catch it. I saw Kurt [Suzuki] put his head down, and I thought, 'Oh yeah.'"
It looked for a moment like the A's were going to squander another scoring opportunity when Cunningham came up to the plate with two outs and runners on first and second. However, Cunningham got a first-pitch slider from Warner Madrigal that hung out over the plate, and he didn't miss it.
"I was looking for a fastball, but I noticed he was throwing sliders, so I had that in the back of my mind," Cunningham said. "It was just a reaction. I got the ball. The team has been really good about getting me everything. It's going to my parents' house in Washington."
A's manager Bob Geren was pleased to see the rookie come up with the big hit.
"He's playing great," Geren said. "He's settling in and looking very comfortabl. I'm giving him a chance to play on an everyday basis. He had the huge hit today. ... He won the game for us, basically."
The A's got things going early in the game, scoring a run in the first inning and then another in the second. Right fielder Ryan Sweeney continued his hot streak at the plate by going 3-for-3 with two RBIs, and he reached base in all five of his at-bats.
Sweeney, who was hit by Rangers starter Vicente Padilla in the second, was glad to pick up the win -- but felt he was thrown at intentionally.
Padilla, who went five innings while allowing two runs on five hits, hit two batters in the game.
"I don't know if he was trying to hit me, but it kind of looked like it," Sweeney said. "Right out of his hand it came right at me, and the guys told me about his history of hitting guys. I was definitely not happy about it."
A's starter Dana Eveland labored through five innings, though he said he didn't feel right from the beginning. Eveland allowed three runs on four hits while striking out six en route to a no-decision. The hurler said he felt a little out of sync, and he had to battle just to keep the team close. He gave up two doubles to Rangers right fielder Nelson Cruz, both of which resulted in RBIs.
"I knew I didn't feel that good from the beginning, but I was able to battle through five innings and do what I could," Eveland said. "It's getting late in the season, and I already have 30 more innings than I've had in my career, so it's starting to catch up with me a little bit."
The A's had a 4-3 lead entering the seventh inning, but reliever Huston Street struggled in relief of Alan Embree, allowing a run on two hits in two-thirds of an inning.
Closer Brad Ziegler, who leads the Majors with a 0.51 ERA, gave up one hit in the ninth and struck out two to earn his ninth save.
Jayson Addcox is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.