It was Smoltz's second rehab start.
Smoltz stuck out two and didn't walk a batter. He threw 60 pitches, 36 of which were strikes.
"Another rung in the ladder," he told nearly 30 reporters -- many of them from Boston -- in a cramped interview room under the stands. "My radar screen has Boston on it. As long as that's the carrot dancing in front of you, you just keep doing what you're doing."
Smoltz said he will likely return to Class A Greenville for his next rehab start and then make two starts for Triple-A Pawtucket. Smoltz said he would be ready to join the Red Sox after those three starts.
Said Boston manager Terry Francona: "We're not going to make our rotation out 21 days ahead of time."
Smoltz's appearance helped the host Fisher Cats set an attendance record with 8,903 fans at the park to watch the veteran right-hander.
Smoltz has been on the disabled list since the beginning of the season while recovering from right shoulder surgery.
Thor Nystrom is a contributor to MLB.com. The Associated Press contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.