With the win, the Cubs finished their 10-game trip at .500 and have won consecutive road series for the first time since taking two of three games in both Milwaukee and Seattle from June 25-30 last season. Chicago is now 15-26 away from Wrigley Field for the year.
"It's nice," Anthony Rizzo said of the trip, "but we need to play better against our division. That's the only way we'll be able to chip away and stay in it. We go home and play good baseball and just continue to play good baseball. That's all we can ask for."
When the Cubs began this trip, they were tied with the Phillies for the worst record in the National League. Chicago is still last in the NL Central, but the team has moved up in the overall league pecking order.
"We didn't play our best against this team," Marlins outfielder Giancarlo Stanton said. "They got four out of six against us. No good."
During this trip, which began with four games in Pittsburgh and included three in Philadelphia and three in Miami, the Cubs won an extra-inning game, only their third in nine such contests, and won two one-run contests. They may not have any clean clothes left, but they're feeling much better about themselves, even if most of the attention by Chicago fans is on recent first-round picks Kris Bryant and Kyle Schwarber, who were each promoted a level Wednesday.
"In terms of the way we've been performing, we've been playing well, and as long as we keep doing that, we give ourselves a chance," manager Rick Renteria said.
Arrieta gave up one run over seven innings and lowered his ERA to 1.98. He topped his career high of nine strikeouts, which he set in his last outing against the Phillies on June 13. The right-hander now has 20 strikeouts over his last two starts.
"He's just commanding his fastball better, and his breaking ball is starting to really get some bite and location," Renteria said. "He's just pitching and attacking hitters. He's got great stuff and it has a lot of movement and when he executes, he's pretty good."
Arrieta said he's not doing anything different but agreed with Renteria that the difference is his command.
"Strikeouts are just a byproduct of throwing several plus pitches for strikes and keeping the ball down," Arrieta said.
Stanton accounted for one of those strikeouts, but also hit his 20th home run in the first inning.
"He was spotting up, using his cutters in good spots, staying on the corners," Stanton said of Arrieta. "He did a good job. ... We didn't put it together."
Chris Coghlan doubled with one out in the first and scored one out later on Castro's double, his 80th hit of the season, second most among NL shortstops to the Rockies' Troy Tulowitzki. But the Marlins tied the game in their half on Stanton's home run off a 2-1 pitch. It was only the second home run Arrieta has served up this season.
Castro delivered again with one out in the sixth against Marlins starter Nathan Eovaldi, driving in Rizzo, who had singled, with his second double of the game. Ryan Sweeney then singled to set up Schierholtz's home run, his third of the season.
Castro finished with three hits and is batting .291, a huge improvement over last season when he batted .245.
"When you're feeling good, good things happen," Castro said. "I go to home plate, I'm feeling good and making good things happen."
Renteria likes what he sees.
"They're playing pretty consistent baseball and having some really good at-bats in key situations, and all the cliches come into play -- timely hitting, good pitching and defense," Renteria said. "Hopefully, it continues. It's a long season and consistency is important."