Hultzen struck out five and held the Rafters to a pair of hits without a walk for his first win. He threw 49 pitches -- 33 for strikes -- in lowering his ERA to 1.62.
"I felt good. [It was] another battle, getting ahead of hitters," he said. "Sometimes the first couple guys, you fall behind, but you get out there and try to get outs. The biggest thing with me is getting ahead of hitters, you can do a lot more that way, so that's the big thing for me. And as the seasons gone on, I've felt better and better."
The left-hander out of Virginia worked a 1-2-3 first inning, striking out the first two batters he faced, then worked around a two-out single by Brian Cavazos-Galvez in the second.
"A lot of the times I'll come out and struggle with the first couple hitters, fall behind, give up a walk or a hit, so that's definitely a confidence booster," he said of the first frame. "To have a strong first inning, that does a lot to your confidence."
He worked a perfect third and struck out two more in the fourth after Adam Eaton started the frame with a leadoff single.
The Mariners prospect hit 94 mph with his four-seamer on the ballpark radar gun and sat in the 92-93 range for most of the outing. He took a seat after closing in on the 50-pitch mark.
"I'd love to stay in there, but the Fall League is about winning and getting work in and getting everyone in there," he said. "I'd like to stay in there, but I understand why we come out pretty early."
Hultzen went 3 2/3 innings in his previous start Oct. 26, allowing two hits and one run with a walk and five strikeouts. He was perfect through 3 1/3 before allowing a solo homer to Brodie Greene, then issuing his lone walk and a double before getting the hook after throwing 58 pitches.
His next start will come Saturday in the AFL's All-Star event, the Rising Stars Game.
"I'm really excited for that. It's a great event, and I feel honored to start that game," Hultzen said. "It's crazy to think about. It's an honor to be in this league and be named a Rising Star, and even more to be named the starting pitcher. It's kind of been a whirlwind the last few days. I'm looking forward to it, though, it's going to be fun."
As far for the AFL experience itself, Hultzen has soaked it all in in his first post-college taste of baseball.
"It's been a lot of fun. These fans are great, they come out, they're very supportive of us, and I really appreciate that as a player," he said.
Reigning Texas League MVP Matt Adams (Cardinals) homered and drove in five runs and Padres third baseman Jedd Gyorko added three hits -- including a homer, three RBIs and three runs for Peoria.
Adams doubled in a run in the third, smacked a three-run homer in the fifth and added a sacrifice fly in the sixth. He's only batting .225 in 17 AFL games, but he's amassed multiple-hit outings in half of his last six.
Astros left-hander Dallas Keuchel (1-2) suffered the loss after being tagged with five runs on 10 hits in 4 1/3 innings.