Colon, who won 75 games for the Indians from 1997-2002, improved to 10-9 and lowered his ERA to 3.43 this season.
"For him, it doesn't surprise me, based on what we saw this spring all the way up to now," A's Manager Bob Melvin said. "There was a pretty good chance, for me, he was going to win double-digit games from the first game he started for us. We've said all along he enjoys what he's doing at this point in time of his career. He's having a lot of fun with it. He's having a lot of fun with his team, and he's a great example for all of our younger pitchers."
Colon put on a clinic against the Indians, scattering five hits. He did not issue a walk. The only run he allowed was on Carlos Santana's seventh-inning homer.
"There are not many guys like him throwing right now," Indians shortstop Asdrubal Cabrera said. "He's still throwing because he's got something. He's a good pitcher."
The Indians stacked their lineup with six left-handed hitters and two switch-hitters against Colon, but he still dominated them with a two-seam fastball.
"We knew it coming, but it was still hard to get," Shin-Soo Choo said. "He was throwing strikes. That two-seamer started on the front shoulder and came back. It looked like a slider."
By the time Colon was finished, the Indians trailed, 6-1, and they were behind, 8-1, before they got a crack at the Oakland bullpen in the ninth. They did score four runs, but it wasn't enough to prevent them from losing for the 17th time in their past 21 games.
"The pitching and the hitting, everybody is in a slump at the same time," Choo said.
A little of everything went wrong for the Indians in the third inning, when the A's scored four runs to essentially put the game away.
It started with Cliff Pennington's ground ball to Cabrera, who ranged up the middle to make a nice play. But his throw was low and first baseman Casey Kotchman couldn't handle it. Cabrera was charged with an error.
Jemile Weeks then sacrificed to move Pennington into scoring position. Right-hander Corey Kluber then walked Coco Crisp. Kluber let the runners get huge jumps and they pulled off a double steal. Santana had no chance, even though the ball got past him on an apparent cross-up with Kluber.
The double steal was costly because Josh Donaldson then hit a grounder that would likely have been an inning-ending double play. Instead, it scored a run.
Kluber completed the disastrous inning with two bad pitches, a changeup that Josh Reddick drilled into right-center for an RBI double and a slider that Yoenis Cespedes hit over the left-field wall for a two-run homer.
"I didn't make pitches when I needed to," Kluber said. "The pitches that killed me were the changeup over the plate to Reddick, and the ball Cespedes hit out was right over the middle, too."
All four of the runs were unearned, and that was all that Kluber allowed in his five innings.
Kluber has a 6.27 ERA in four starts. Manager Manny Acta said it's still too early to make any judgments about the 26-year-old right-hander.
"He's got a good fastball, a good cutter and good slider," Acta said. "We're not going to make a knee-jerk reaction. We brought him up to take a look and that's what were going to do."
The silver lining to all of it was the Indians' four-run ninth. Choo hit a two-run homer and Brent Lillibridge hit a two-run homer as a pinch-hitter. The Indians knocked out Evan Scribner and Jerry Blevins before forcing Melvin to bring in closer Grant Balfour, who struck out Ezequiel Carrera to end the game.
"I like the fact the guys fought till the end," Acta said. "They aren't going to roll over. Unfortunately, it's not easy to make a comeback from that many runs down."