The Indians prospect yielded two hits and struck out seven over a season-high eight innings as the Double-A Akron Aeros coasted to a 6-0 blanking of the Altoona Curve.
Packer (4-9) walked one, hit a batter and faced only four over the minimum in matching the longest outing of his three-year career. After Matt Curry singled with one out in the fourth, the Curve got just one more baserunner against the 23-year-old left-hander as Juan Diaz reached on an error on the seventh.
"Everything was working. I had command of my fastball and my secondary pitches and I stayed ahead of the count," said Packer, who also throws a slider and a changeup. "That let me go into the eighth inning."
The 2009 32nd-round Draft pick struggled for much of the season, losing eight of his first 10 decisions. But he's begun to turn it around, giving up four runs while fanning 20 over 23 1/3 innings in his last three starts.
"I've just kind of been slowly figuring things out and things are starting to click in the games and I've been able to throw well," Packer said. "I've been up in the zone and I've been working with pitching coach Tony Arnold to get where I can repeat my delivery over and over again. That's been my biggest problem and it's made all my pitches sporadic."
Outings like Tuesday only reinforce the notion that the additional work is paying off.
"I think that the biggest thing is that it's helping me build my confidence and it's showing me the work I'm doing is doing something good," the Tennessee native said. "I can keep my confidence up, knowing that I can pitch like that."
Packer's goals for the rest of the season are simple.
"I just want to be consistent," he said. "I want to make quality starts, I want to take my team into the sixth or seventh inning and have a chance to win every start."
Rob Bryson pitched a scoreless ninth in his Akron season debut.
Beau Mills hit a three-run homer, his third in four games and 10th of the season, while John Drennen reached base three times and scored twice for the Aeros.
Altoona starter Michael Colla (4-7) lasted 4 2/3 innings and was charged with five runs on six hits and four walks. He struck out three in dropping his sixth straight decision.