Not long after becoming the first I-Cub to hit for the cycle in 14 years, Colvin had his ninth-inning single switched to an error after the official scorer reviewed a videotape of the play.
Iowa trailed, 13-7, with two outs in the ninth when Colvin pulled an 0-2 pitch sharply to the right side. The ball caromed off the glove of first baseman Jerry Sands as Colvin reached safely.
Almost immediately, it was ruled a hit, making Colvin the first member of the Cubs to hit for the cycle since Robin Jennings on Aug. 15, 1997. After the game was over, however, the ruling was changed and Sands was charged with an error.
"The official scorer took a look at the video after the initial call. It was clear that while the ball was hit hard, Sands did not have to move -- it was hit right at him," Isotopes media relations director Steve Hurlbert said. "After looking at that, he made the change, but it was not without a lot of deliberation. At the end of the day, we want to get the call right."
Bryan LaHair followed with a single that chased Isotopes starter John Ely (3-5) and Welington Castillo drilled his second homer of the game to get Iowa within 13-10. Brad Snyder singled, but the Cubs' rally fizzled when Scott Moore lined to third baseman Ivan De Jesus.
Colvin settled for a three-hit night in his second game since returning from the big leagues. He doubled in the first, legged out an RBI triple in the third and slugged a solo homer with one out in the fifth before striking out in the seventh.
The outfielder/first baseman has had an up-and-down first half of the season. He batted .113 with two homers and eight RBIs in 28 games with Chicago, which sent him to the Pacific Coast League on May 17 in an attempt to get him more at-bats.
After a dozen Triple-A games, Colvin returned to the Majors on May 31. His average dropped to .105 and he rejoined the I-Cubs earlier this week.
The Clemson product went 0-for-4 with three strikeouts on Thursday but raised his average 30 points to .271 on Friday.
Ely (3-3) picked up the win, despite allowing nine runs -- seven earned -- on 11 hits and a walk over 8 2/3 innings. He struck out eight.