With the win, the Dodgers now lead the Rockies by five games in the National League West. The Rockies lost again to the Giants and lost their fourth straight overall. The Giants are 7 1/2 games back.
The blast marked Ethier's Major League-leading sixth walk-off hit of the season -- fourth via the long ball -- and it left him smiling and shaking his head while answering questions in a boisterous postgame clubhouse.
"You pinch yourself now," said Ethier, who has nine walk-off hits since the start of the 2008 season.
"To hit one in a season, to hit one in a couple of years is a great thing.
"To hit more than a couple? I don't know what's going on. But it's fun and I'm going to enjoy it while I'm doing it."
It seems that Dodgers manager Joe Torre also has given up on trying to explain what Ethier's done this season.
"As Yogi [Berra] would say, 'It's déjà vu all over again,'" Torre said. "You've seen him do it, you want to visualize it. And when he does it, it's just surreal."
What's eerie is how all of Ethier's walk-off homers have played out in similar fashion: Ethier unleashing a violent swing, the ball flying into the right-field bleachers and his teammates mobbing him at home plate.
Against the Pirates, Ethier connected on what Dumatrait felt was a good pitch.
"I went two-seam in and it was just above the knees and maybe even in a little bit and he just dropped the head [of the bat] a little bit," Dumatrait said.
"He beat me. I went and looked at video and it was down. It was a little bit off the plate in."
Even if the pitch was one that the Pirates wanted to throw in that situation, it was one that Ethier was prepared for.
Ethier, whose 30 home runs are the most by a Dodgers player since Adrian Beltre hit 48 in 2004, said that based on his at-bats against Pittsburgh starter Zach Duke, he thought that the Pirates might test him in a similar fashion.
And as soon as he saw the ball, he readied to swing.
"I made up my mind as I saw it out of his hand," Ethier said.
That split-second decision and all the factors involved, describe the maturation that Ethier has undergone this season with the Dodgers.
He's slowly turned into one of the Dodgers' more fundamentally sound hitters and one of the more dynamic young hitters in the game.
"We talk about guys growing up and this kid is just growing as he goes," Torre said. "He's been though some rough spots, he fights himself, he probably gets himself out a lot of times -- but he's not afraid of the spotlight."