With his one-run, six-inning performance in the series finale, Hellickson improved to 4-2 in his career with a 2.61 ERA in 69 innings against the Marlins. In 2016, he was 3-1 with a 2.01 ERA in six starts.
Hellickson repeatedly got the Marlins out on changeups.
"We keep giving him that first strike, where he runs that ball off the plate and we're swinging," Marlins manager Don Mattingly said. "I saw numerous swings where you know it's ball one, really. Instead of being 1-0, it's 0-1, and that's a different count."
Mattingly's takeaway is the Marlins can improve off the right-hander by not chasing.
"That's one of the areas we've got to improve on, is not chasing out of the strike zone, early in the count, to put him in situations that he can kind of do what he wants," Mattingly said. "We've got to force him onto the plate and understand which balls stay on the plate and which balls don't stay on the plate. That's kind of the battle with him."
Of the 94 pitches Hellickson threw, 35 were changeups. In the fourth inning, the Marlins had a chance to break through after being down 2-0. They had runners on first and third with no outs, and couldn't score.
Hellickson fanned Giancarlo Stanton with a changeup, and with the same pitch retired Marcell Ozuna on a pop up to shortstop. J.T. Realmuto lined out to short on a changeup.
"That's what I'm trying to do," Hellickson said. "Stay down in the zone, get weak contact. I'd like to get a little more groundballs than I am. But I'll take weak flyballs all day."
Realmuto did provide the Marlins with an RBI single in the sixth inning, scoring Stanton, who had doubled.
"He does a good job moving the ball around on us," said Realmuto, who had two hits. "He doesn't leave a lot of pitches over the plate, and then works his changeup in whenever he wants to, really. Throws it for strikes when he wants. Throws it for a chase pitch when he wants. He does a good job keeping us off balance."
Martin Prado had a chance to drive in a run in the fifth inning, as Miami had runners on first and second with two outs. But on a changeup, Prado popped out to catcher Andrew Knapp.
"He really controlled the changeup. He was throwing it in every count," Prado said. "He threw the ball well today.
"We're just not hitting at the right moment. We're not getting the big hit. I think that's the product of baseball: sometimes, it doesn't happen."