Crew chief Jerry Layne did talk to home-plate umpire Mike DiMuro after the Nationals sixth, but play was never stopped, and Cubs manager Rick Renteria said there was never any discussion about delaying the game.
The fog rolled in during batting practice, and didn't leave.
"I don't know that I've been here on the other side as a visitor or otherwise and experienced that," Renteria said. "It was interesting."
Ruggiano hit a tie-breaking two-run double with two outs in the seventh to lift Chicago to a 5-3 win over Washington, giving Neil Ramirez his first Major League win. It'll be a game they'll remember.
"It's kind of fun -- it mixes it up a little bit," Ruggiano said.
Wrigley Field is only a few miles from Lake Michigan, which was part of the reason for the fog. The lake is cooler than usual and the wind off the lake is creating the cool and foggy conditions, according to meteorologists.
This wasn't the first time it's been foggy at Wrigley. Last year, the Reds and Cubs played in murky conditions on June 10, although Brandon Phillips could see well enough to hit a grand slam in a Cincinnati win. On May 8, 2012, the Cubs and Braves dueled in the fog.
It was not as difficult to see as it was for the Chicago Bears on Dec. 31, 1988, when they played the Philadelphia Eagles at Soldier Field in a NFL playoff game, in what has been dubbed the Fog Bowl.
"The fog was tough," Ruggiano said of Thursday's game. "Obviously, you saw Span lose a ball and it got a little more tough in the fifth, sixth innings. In the last inning, it seemed like it cleared, and then at the end it came right back. I didn't have anything out there so it was OK. As long as the ball stayed lower than the lights, it was all right."
Ruggiano started in right field, then moved to center when Junior Lake had to leave the game after colliding with a metal door in the outfield wall.
Span had the toughest time.
"There's nothing you can do to prepare for that," Span said of the conditions. "I don't think I've ever played in a game with that much fog. You just try to concentrate and try to keep your eye on the ball as long as possible and hope that you can kind of gauge where the guy is gonna be once it's hit."
There are no special fog goggles to help an outfielder.
"You know what, the ball that I didn't see, I didn't know it was even coming at me, to be honest with you," Span said. "I didn't know where it was. I finally figured that the ball was coming toward me because everyone was looking at me and pointing in my direction ... but it is scary.
"Once I figured out the ball was coming toward me, I didn't want to look up because the last thing I wanted was to let the ball hit me in my pretty face."
How weird is it to be dealing with fog on June 26?
"The Midwest, man," Span said. "I played in Minnesota for five years, and it's unpredictable. I never remember a game like this, but all year round it's unpredictable. You'll get snow in October, or it can be 85 degrees."
Nationals manager Matt Williams said Ian Desmond talked to crew chief Jerry Layne about whether they would consider stopping the game after the sixth.
"But it's not like rain where you've got radar and you can see, 'OK, well, we'll delay it 15 minutes and it'll be gone,'" Williams said. "You just have no idea. But both teams had to play in it, and they got more than we did."
Several players had seen foggy games, but had not played in them until now.
"I remember seeing on television where they had to delay the game because the fog was so bad," Williams said. "It's hard. You have to make sure you communicate out there. Some innings it was better than others, but for the most part, it was difficult."
It was a first for Ruggiano.
"The only thing I can compare it to is a snow game I played in where the ball went up and I don't think anyone saw where it landed," Ruggiano said of the Minor League game in Toledo. "We had to call the game. I was talking to Nate [Schierholtz] and he said last year, they had a game against the Reds and they never called it. I said, all right, let's just play the elements."