PHILADELPHIA -- Jordan Yamamoto's ERA is no longer perfect, but the 23-year-old's winning percentage remains unblemished.

After beginning his big league career with back-to-back scoreless outings of seven innings apiece, Yamamoto allowed a pair of first-inning runs before settling in for a 6-4 victory over the Phillies on Sunday at Citizens Bank Park.

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The righty struggled out of the gate, walking each of the first three hitters to load the bases after being staked to a 1-0 lead in the top of the first. After retiring Jay Bruce on a popout, Yamamoto allowed a two-run single to Jean Segura, ending the right-hander's franchise record 14-inning scoreless streak to begin a career.

Yamamoto quickly turned things around, however, retiring 14 of the final 16 batters he faced following Segura's knock. The righty finished with just the two runs allowed on two hits and four walks, while striking out seven over five innings.

"It was definitely one of those times where I just needed to buckle down," Yamamoto said. "It isn’t me to give up three walks to start the game, but hey, things happen. I just came back in the dugout and said, ‘Take it one pitch at a time and let it roll.’ So I just went out there and threw it like I’ve been doing the last two games, throw the ball over the plate and trust my catcher."

The three-game triumph in Philadelphia marked the third sweep of the season for the Marlins, a team that did not sweep a single series in 2018.

"We’re a bunch of misfits," closer Sergio Romo said at the start of the series. "We’re those guys that they’ve pushed to the side. We’ve got a lot of fight though. It’s great to be a part of."

Miami manager Don Mattingly got a good laugh when asked about that “misfits” label.

"I don’t know if we’re a bunch of misfits or not," Mattingly said, "but I think we’ve seen that basically nobody really gives us a chance."

Call them what you will, but it's hard to argue with the sentiment, especially after this weekend.

On Friday, the winning run scored on a chopper up the third-base line off the bat of César Puello, acquired from the Angels on June 19. One day later, catcher Wilkin Castillo -- playing in his first MLB game in more than a decade -- delivered the decisive two-run double.

Meanwhile, Garrett Cooper -- acquired by the Yankees in July 2017, only to be shipped to Miami that winter -- went 3-for-5 with a home run Sunday, extending his career-best hitting streak to 14 games.

As for the pitching, three different relievers closed out the three wins. Romo, a 12-year veteran, locked down the victory Friday, before José Quijada and Nick Anderson -- a pair of rookies -- each earned their first career save on Saturday and Sunday, respectively.

As for Yamamoto, he was a 12th-round pick by the Brewers in the 2014 Draft and had never pitched above Double-A until making the jump directly to the Majors 11 days ago. He now has three wins in as many big league starts, all while putting up a 0.95 ERA.

It's not just Yamamoto, though. The Marlins' starting rotation -- which currently doesn't feature a pitcher older than 26 -- has a 2.60 ERA over the last 15 games. That's the second-best mark in the Majors dating to June 8, trailing only the Dodgers, who currently have the best record in baseball.

“You start to get a lot of different pieces in the lineup that can do something, and when you’ve got pitching, you’re going to be in a lot of games," Mattingly said. "So if we can keep getting some key hits, we’re going to be all right.”

The Marlins have won four straight games and are 20-15 since starting the season 10-31.

"The guys have kept playing. I think that’s one of the things you want to see with a club that started the year like we did," Mattingly said. "We knew we were young, we know we’re still in the build, but you just want to see improvement and you’re hoping that you just get better and better as the season goes on."