PEORIA, Ariz. -- Jordan Yamamoto has one primary reason for his Arizona Fall League success -- aggressiveness.
The Marlins right-hander is wasting no time against opposing hitters, and he's posting dominant results. On Monday, Yamamoto continued his impressive AFL campaign with five scoreless innings in the Salt River Rafters' 10-inning, 5-4 loss to the Peoria Javelinas at Peoria Sports Complex.
• Gameday
Yamamoto allowed only one hit and one walk while striking out six. Miami's No. 17 prospect lowered his Fall League ERA to 2.08 through six starts.
"Just working fast, throwing strikes, I'm just getting outs, that's pretty much what it is," Yamamoto said. "That's what I try to work on -- just get guys out early in the count."
It may have been Yamamoto's final AFL start, although he will be lined up to pitch in the AFL championship game on Saturday, if Salt River wins the East Division. The Rafters have a 1.5-game lead over Mesa with three games remaining.
Yamamoto worked an efficient 1-2-3 first inning against Peoria, notching a pair of strikeouts. In the second, a leadoff single was erased by a strikeout/caught-stealing double play, and Yamamoto worked around a two-out walk for another clean frame.
From there, Yamamoto continued to be efficient. He worked around a two-out error in the third and retired the last six batters he faced in perfect fourth and fifth innings, which included a pair of strikeouts in the fourth.
Yamamoto has allowed more than one run in only one of his six AFL starts. He had five or more strikeouts in four of those outings and has pitched five innings in four consecutive starts.
"It's always a good time. For me, it's just having fun," Yamamoto said. 
Yamamoto made only 13 starts during the Minor League season due to injury. In three outings for Double-A Jacksonville, he went 1-0 with a 2.12 ERA and 23 strikeouts.
After pitching only 68 2/3 innings during the Minor League campaign, Yamamoto has used the Fall League season to get more work in against some top hitting prospects.
"I really needed these innings to help me out," Yamamoto said. "I've faced elite hitters in all of professional baseball. Just facing these guys, it really pushes me to be the best I can be."
After Peoria tied the game in the ninth, Salt River took a 4-3 lead in the 10th on an RBI single by Nationals No. 2 prospect Carter Kieboom, who went 4-for-5. However, Peoria tied the game again on a wild pitch in the bottom of the inning, then scored the winning run on a Salt River error for a walk-off victory.