The right-hander threw eight pitches total -- four fastballs and four curves.
"I heard that he did really well," Cubs manager Joe Maddon said from Wrigley Field. "It's just about health. If the guy is healthy and he's ready to rock n' roll, you put him in the ninth inning."
Kimbrel induced a fly out and a groundout before striking out his last batter, reportedly reaching 95 or 96 mph on the radar gun.
The Cubs still won't put a timeline on him coming up to the majors. The team will know more as he recovers from each outing.
Kimbrel will pitch again on Thursday or Friday, according to general manager Jed Hoyer.
"He's felt good, but we're not going to rush to judgment on any one outing," Hoyer said.
Kimbrel signed a 3-year, $43 million deal earlier this month and will take over closing duties as soon as he's ready. An eight-pitch outing on Tuesday was a good sign, but perhaps it went too quickly.
"It's one of the challenges when these guys go down on these rehab assignments, actually getting enough work in," Hoyer said with a smile. "Good first outing in a real game."