The 6-foot-7 right-hander struck out four, walked two and faced just one batter over the minimum in the Reading Phillies' 2-0 blanking of the Richmond Flying Squirrels.
"I felt I was on today," Aumont said. "I misfired a couple, it happens. Overall, it's a great day for me. I'm happy with this.
"I felt pretty well out there with the guys. It's not only my game, the guys behind me did a great job, especially catcher [Tuffy Gosewisch] calling the game. You've got to give those guys credit."
The 11th overall pick in the 2007 Draft by Seattle, Aumont was the first Quebec native to be taken in the first round. He made eight starts for Class A Wisconsin in 2008 but was used exclusively as a reliever at Class A Advanced High Desert and Double-A West Tenn in 2009 before the Phillies returned him to a starting role this spring.
Other than a seven-inning start on June 3, 2008, Sunday's six-inning outing was his longest as a professional.
"It's still early in the year. Six innings was good for me today," Aumont said. "Obviously, I would have loved to have gone (out there) for the seventh inning and see what would have happened. But I'm happy with what happened today. The bullpen did a good job. They came in and closed the game out."
Aumont has improved in each start this year after a rough Phillies debut in Spring Training. He allowed five runs on two hits and three walks while retiring only two batters in an exhibition game against Florida State on March 3.
Aumont acknowledged that he felt pressure to make a good impression after being part of a trade involving a Cy Young Award winner.
"The kid came in a big trade," Phillies pitching coach Rich Dubee said at the time. "He comes in, he wants to impress. He's pressing a little bit."
After posting a 5.91 ERA and walking seven in his first two starts for Reading, Aumont took great strides against Harrisburg on April 19. Despite suffering the loss, he allowed one run on five hits over five frames, striking out five without walking a batter.
Aumont, MLB.com's No. 47 prospect, seemed comfortable on Sunday afternoon. He did not allow a baserunner until Conor Gillaspie drew a leadoff walk in the fifth inning. Gillaspie later was erased on a double play.
Aumont (1-1) turned the ball over to reliever Chance Chapman for the seventh inning with Reading holding a 1-0 lead. After recording two outs, Chapman yielded a single to Gillaspie for the Flying Squirrels' only hit. Michael Schwimmer pitched the final two frames, striking out four, to earn his second save.
Reading plated an unearned run in the first, then added an insurance run in the seventh when Freddy Galvis walked and scored on Domonic Brown's triple.
Richmond starter Clayton Tanner (1-2) took the loss, yielding an unearned run on five hits and four walks in four innings.