"I was just trying to get a good pitch to drive him in, there were two outs," Stewart said. "I was just hoping to get a fastball and was fortunate enough to put a good swing on it. I didn't think it was going to go out, but I had a good feeling about the swing that it was going to go off the wall and get the runner in -- but it went out for me."
Stewart, who finished 1-for-3 with two RBIs and is hitting .246, waited 17 games to hit his first AFL homer, but it turned out to be the perfect game to break out the power as Orioles executive vice president of baseball operations Dan Duquette was in attendance.
"It's definitely a good feeling to homer when he's here," Stewart said. "Our farm director [Brian Graham] is here, too. I picked a good time to get the first one."
Stewart's homer, a two-run shot that came on a 1-1 pitch, capped a three-run sixth in which the Javelinas offense finally showed some life after being no-hit through the first five innings.
Michael Peoples (Indians) got Mesa off to a strong start, twirling four perfect innings in his best Fall League start thus far. The 25-year-old right-hander struck out three and threw 28 of his 38 pitches for strikes.
"It looked like he was doing a good job of mixing his offspeed, throwing strikes," Stewart said. "Not too many overpowering pitches, but he knows how to use his pitches and was putting them where he wanted to, didn't give up a hit."
Ryan Newell (Marlins) came on in relief and walked a pair, ending the bid for a perfect game, but continued the no-hitter with a scoreless fifth.
Left-hander Jarlin Garcia, Miami's No. 3 prospect, took over in the sixth and retired the first batter of the inning before Kean Wong (Rays) singled up the middle to begin the rally. Two batters later, Chad Wallach (Reds) drove in a run with an RBI double before Stewart finished the inning with his homer.
"Finally, when Kean got that first hit, we could take a deep breath, and right after that, hits after hits after hits," Stewart said. "Hitting is contagious. When one guy gets it going, usually the other guys aren't far behind and that's what we were able to do."
Before Peoria mounted its comeback, Mesa had held a 2-0 lead.
Marlins' No. 4 prospect Brian Anderson, who is hitting .345 through 16 games, led off the second with a solo homer. The homer was Anderson's fourth, tying him with Mitch Garver (Twins' No. 24) for the AFL lead.
Athletics No. 7 prospect Yairo Munoz, who finished 2-for-4 with a pair of doubles, drove in a run of his own with an RBI double later in that inning.
Franklin Barreto (A's No. 1, No. 42 overall) gave Mesa a lead with an RBI single in the eighth, but the Javelinas came back once again with two runs in the ninth to seal the win.
William Boor is a reporter for MLB.com. Follow him on Twitter at @wboor. This story was not subject to the approval of Major League Baseball or its clubs.