The two athletes had known for weeks that there was a chance they'd be playing in their respective games at the same time, and that they'd be finishing at close to the same time.
So as soon as the final whistle blew out west, Julie raced to learn the news she had hoped all night to hear.
"I shook the other team's hands really, really fast and was looking around," she told the Inquirer and Daily News late Sunday night. "I had to hear it from at least three people just to make sure it was true and real, and I had some pretty raw emotion."
She didn't have to look far to find sources. Teammates mobbed her, and head coach Jill Ellis gave a big hug.
The moment was televised nationally on ESPN, and of course it went viral thanks to the national team's social-media accounts.
"I'm just so proud of him, and obviously the team in general," Julie said. "It was emotional to not be there to celebrate it with him, but I'm just super-excited."
At halftime, she heard from fans in the stands that the Eagles were in good shape. But she knew there was still plenty of time left at Lincoln Financial Field — and there was in her game, too. Though she scored what proved to be the Americans' winning goal, Denmark scored first on the night.
"People gave me smiles and nods, just to give me updates," she said. "But I knew that we had another half, so I knew I had to stay focused. This was a big game for us as well."
Julie will be in Minneapolis to cheer Zach on at the Super Bowl. Before then, she'll be in Philadelphia to take part in the city's celebration of the Eagles' NFC title.
She won't be the only U.S. national team star at the party: Delran native Carli Lloyd has long been a huge Eagles fan.
"She just looked at me and said, 'Go Birds!'" Ertz said of Lloyd's reaction Sunday night. "She knew that I was emotional and needed my time to kind of just take it all in. She definitely was super-excited."
In the hours before the game, Julie and Zach were in regular contact. They have a habit of talking to each other a lot on game days, even when they're both in Philadelphia. This time, they had nearly 4,000 miles between them.
"We FaceTimed for a little bit — we always do," Julie said. "He had to go before I did, so we talked a little bit on text and said a little prayer."
After the Eagles game ended, Zach was shown the video of Julie's celebration.
"Oh, man — it's emotional for me," he said. "I wish I could see her, obviously. It's tough not having her here, but I can't wait for her to get home, and to celebrate with her."
Because of Julie's game, Zach ended up being surrounded by teammates who were with their wives while he wasn't with his. He noticed.
"She's always there for me, through the highs and lows. That's all you can ask for from someone that you love. I hope I do the same for her," he said. "We just love doing what we do. This is a short time in our life, playing at this level. Eventually, we'll settle down and stop playing sports."
Soccer and football fans alike in Philadelphia hope there are still plenty more celebrations to come before that happens.
Staff writers Ed Barkowitz and Marc Narducci contributed to this report.