With Drew Smyly expected to miss at least the first two months of the season, Miranda has a chance to fill Smyly's void, and he certainly looked the part in picking up his first win in the Mariners' fourth straight victory.
"I was just being a lot more aggressive today," Miranda said through an interpreter. "Obviously a lot of early strikes, so that helped out a lot."
Miranda didn't allow a baserunner until a two-out single by Christian Yelich in the fourth, and Miranda escaped his only jam -- two on with two outs in the sixth -- when he got Yelich to fly out to right.
"Great outing by Ariel tonight," manager Scott Servais said. "He really pitched much different than his last time out, when he threw a lot of off-speed pitches. Tonight, he was very aggressive with his fastball. That was great to see. He was really in control of the game."
Miranda hadn't completed six innings in either of his first two outings, both against the Astros, but he was more in command in this start, as his fastball location was sharp from the beginning and he didn't issue any walks.
"That's what he lives off of, and he should," Servais said of Miranda's fastball. "He's got a nice ride up in the zone. His secondary pitches, the split-change he throws has really come along, and he threw some pretty good sliders tonight to some pretty decent left-handed hitters.
"His confidence is growing. Not making our team originally out of camp, and then with the Smyly injury and stepping up like he has, that's why we had the depth. When [general manager] Jerry [Dipoto] put the club together, you knew we were going to need six or seven or eight starters sometimes. So it's nice for him to step up and just pick up where he left off last year."
The Marlins, who had never faced Miranda, were impressed by the left-hander.
"He's got good stuff," Miami manager Don Mattingly said. "Obviously we haven't seen him before. He looks good when you look at him on video. He's got a good changeup to the right-handers, and he's got enough velocity to get you started. He threw the ball good."