Cunningham went 3-for-5 with two homers, a triple and five RBIs to power the last-place Mesa Solar Sox to a 13-7 Arizona Fall League victory over the league-leading Salt River Rafters.
"I've been out for about six weeks, so it was just getting back into the swing of things," he said. "I think before I just had too much adrenalin. I wasn't getting my pitch to hit, I was going out of the zone chasing pitchers' pitches.
"I didn't make any mechanical changes, it was all mental. I wasn't going after balls down and out of the zone.
Selected in the 18th round of the 2008 Draft, Cunningham has battled a injuries for much of his career.
He was sidelined for the entire 2009 campaign with an ACL injury, and he was placed on the disabled list again in August with concussion-like symptoms, missing Class A Advanced Bradenton's last 48 games. He made two appearances in the Gulf Coast League before deciding he was healthy enough to cope with the AFL workload.
On Monday, those troubles looked to be a thing of the past. He laced a run-scoring triple off the base of the center-field wall in the second inning, and he belted a solo homer to left field off Rafters starter Stephen Fife (Dodgers) in the third.
"I felt good today, really comfortable," said Cunningham, who entered the game batting just .172 with two extra-base hits in eight appearances. "I was just trying to see the ball better. [Fife] left a curveball up and I was able to get the barrel on it."
The 21-year-old then deposited a three-run long ball over the left-field fence in the fifth to extend the Solar Sox's advantage to 10-1.
"[The Astros' Jason Stoffel] started me off with a slider and then he tried a fastball in," Cunningham recalled. "The catcher went out to talk to him and I thought I would get another fastball. He hung a slider, but I was able to stay back on it.
"I was hoping it might hit the wall, then I could get a double there and maybe then a single in my last at-bat. I wasn't trying to think about it, but my teammates kept saying I had the hardest two out of the way."
Cunningham had two more shots at trying to add to his cycle bid, but he lined out to short in the sixth and grounded out to second to end the eighth. It didn't seem to faze him.
"I'm coming from Spokane, Washington. Not many people get to do what I'm doing," he said. "Taking batting practice and seeing some of the names on the backs of the jerseys is awesome. On paper, they have more on their resume, but when I get out on the field, I know I belong here."
In 80 Florida State League games with the Marauders this year, Cunningham hit .258 with 15 homers and 51 RBIs.
Robbie Grossman (Pirates) smacked his fourth homer of the fall, reached base three times and drove home two runs to help the Solar Sox improve to 4-8. Joe Mahoney (Orioles) went 3-for-5 with a homer, two doubles, three RBIs and a pair of runs scored.
Nolan Arenado (Rockies) was 3-for-5 with a solo long ball and three RBIs for Salt River (9-3).
White Sox farmhand Terry Doyle (2-0) allowed one hit -- a solo homer -- and a walk while striking out four batters over five innings. After allowing Arenado's first-inning homer, he faced the minimum the rest of the way. It marks Doyle's second consecutive impressive start. On Oct. 11 against Scottsdale he retired all 12 batters he faced as Mesa carried a perfect-game bid into the sixth.
Fife (0-3) took the loss after surrendering seven runs on seven hits and two walks over three frames.
Ashley Marshall is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.