The family of Steven Matz of the New York Mets...

The family of Steven Matz of the New York Mets poses for a photograph before a game against the New York Yankees at Citi Field on Friday, Sept. 18, 2015. Credit: Jim McIsaac

Standing on the sidewalk outside Citi Field, Ron Matz turned toward his sister-in-law, who was wearing the jersey of his son, Steven.

"When I married into the family," he said, "did you ever think that you would be wearing my name on your back?"

The entire family, each member wearing a Steven Matz jersey, burst into laughter.

The tone changed, though, when Matz allowed a few baserunners and a run crossed the plate in the first inning Friday night. Seated on the field level down the first-base line, Ron Matz took time after the top of the first inning to analyze his son's rough start.

"He was a little amped up," he said. "The ball hung a little. But it wasn't hit hard. He has to keep the ball down. He'll settle down."

And he did. Matz's entourage cheered as he induced a grounder to complete six innings of work, in which he allowed one run, seven hits and one walk to lead the Mets to a 5-1 win over the Yankees. The Stony Brook native and Ward Melville graduate improved to 4-0 with a 1.80 ERA in six starts.

"It's incredible, 4-0. What a night," Ron said after the game. "Started a little shaky but he settled down."

For a variety of reasons, the start was the most important in Matz's budding major-league career. He was looking to get the Mets one win closer to securing a playoff spot. He was auditioning for a potential start in the postseason. He was facing the Yankees. And, of course, he was pitching in front of friends and family.

"This is kind of what you want growing up," Matz said. "These are the games you're playing in your backyard and you're imagining to yourself that this is what you're playing. So that's what it was like today and it was a lot of fun."

In the Mets' family lounge prior to the game, Matz's sister, Jillian, was asked what her brother did at their Stony Brook home Friday morning with such an important start on the horizon.

"He laid on the couch," she said, "watching a show about people hunting in Alaska."

Again, laughter from the Matz family.

"We were just having normal conversation," she added. "I asked if he was nervous just as he was walking out the door and he said no not yet. I get really nervous when he's about to go on and then I feel a lot more calm because I know he is going to do well."

And he did, becoming the first player in franchise history to allow two runs or fewer in each of his first five career starts. Matz also became the second homegrown Long Island baseball player to recently defeat the Yankees, following his close friend Marcus Stroman, a Patchogue-Medford product who led the Blue Jays to victory at Yankee Stadium on Saturday.

"It seems like every situation that he steps into, if it's an important game, he usually rises to the occasion," Ron said. "Hopefully, he'll continue to do that."

"It was a lot of fun," Matz said of pitching in the Subway Series. "The atmosphere was great. It gets your adrenaline going and it was a lot of fun to be part of."

Fun for Matz's friends and family, also.

Matz's uncle, Gary Moller, described how, during his nephew's debut in June, he sat in the luxury suite when Matz was pitching and ran down to their seats in the front row when he was batting. His former coach at Ward Melville, Lou Petrucci, fondly remembered when Matz outdueled Stroman, 1-0, in a game in 2009 that drew a scout from every major-league team. His uncle and aunt, Kenneth and Lynn Lalia, reminisced about one Christmas Eve when Matz rolled up some snowballs and threw them at a bench, which he used as a strike zone.

"He was throwing strikes!" Kenneth said.

Matz's grandparents -- Joan and Herb Matz of Commack -- couldn't be at the game because his grandfather is recovering from surgery. But Herb's goal is to be in attendance should his grandson pitch in the postseason.

"He wants to be there," Ron said. "He gets a kick out of seeing his name on people's backs."

Bert Moller, Matz's 82-year-old grandfather who became an Internet sensation when his animated reactions during his grandson's debut were captured on camera, was in attendance. On the train ride to Citi Field on Friday, he said he was stopped by multiple fans.

"They recognized me!" he said. "They said, 'Hey Grandpa Bert, can we take a picture with you?' "

He also said that, after being featured on television and in newspapers, he began receiving phone calls from people he hadn't spoken to since grammar school more than 60 years ago.

"I had two requests for dates," he said, "and one proposal for marriage."

If she marries into the family, she'll need a Matz jersey.