The Mariners prospect recorded 10 strikeouts and allowed two hits over a career-high 6 2/3 innings Saturday as the Double-A Jackson Generals blanked the Birmingham Barons, 2-0.
Paxton did not allow a hit until Jose Martinez singled with one out in the fifth. He struggled a bit after that, walking the bases loaded before fanning Greg Paiml to end the inning.
The 2010 fourth-round Draft pick exited after allowing a two-out single in the seventh to Jason Bour on his 96th pitch.
"Tonight, there were a lot of fastballs," Paxton said. "I couldn't find my curveball tonight, but I got some changeups in there."
Paxton has endured a whirlwind few months. He signed with Seattle on March 7, then dominated the Class A Midwest League with a 3-3 record and 2.73 ERA for Clinton. The Mariners skipped him a level to Jackson, where he improved to 2-0 and has not allowed more than two earned runs in his first six starts.
"I've just been working on pounding the strike zone and making these guys hit the ball," he said of his Southern League success.
The 22-year-old left-hander has 121 strikeouts over 88 innings across the two levels.
"Throwing inside is a big thing for me," said Paxton, who's fanned at least 10 batters five times in 16 starts. "I've got some good life on my fastball, and when I get two strikes I like to come inside and force the guys to swing on it."
A native of British Columbia, Paxton also was selected to participate in last month's All-Star Futures Game, where he needed only seven pitches to toss a perfect inning for the World Team.
"It was a great experience and a lot of fun," he said. "[I learned to] attack hitters and make them swing the bat, go right after them and not worry about who is at the dish."
Paxton originally was picked by the Blue Jays in the first round of the 2009 Draft but did not sign. Ruled ineligible to return to the University of Kentucky by the NCAA, he signed to pitch in an independent league before re-entering the Draft. He signed with the Mariners for $942,500.
Because of the late signing, Paxton was held in extended spring training to build up his innings and did not make his professional debut until April 27. All in all, it's been a wild ride.
"I feel pretty good about it," he said. "I've been working really hard and I want to keep on going and have a successful year. I want to work on my changeup and get that consistent, that's my biggest project. Continue to be successful and take that into next year."
Brian Moran allowed a hit over 1 1/3 innings and Edward Paredes walked two in the ninth before recording his first save.
Carlos Triunfel smacked an RBI double and Vinnie Catricala slugged a solo homer for the Generals, who have won three of their last four games.