For the Nationals, who began playing in the US capital in 2005 when the Montreal Expos moved there and changed their name, the win put the finishing touches to a stunning turnaround after they began the season with a miserable 19-31 record.
Anthony Rendon kicked off the Nationals rally in the seventh with a solo shot off Greinke, and Howie Kendrick came up with a go-ahead two-run blast off Astros reliever Will Harris two batters later.
It wasn’t the first time Kendrick had come up in a big moment for his team. His grand slam in the 10th inning of the National League Division Series felled the 106-win Los Angeles Dodgers, and he again struck the decisive blow for the Nationals, slapping a cutter from Astros right-hander Harris off the right-field foul pole to erase a 2-1 deficit.
Greinke, who had been excellent through his first four innings, departed after 6 1/3, charged with two runs on two hits and two walks with three strikeouts.
Washington left-hander Patrick Corbin made that lead stand by completing a three-inning stint of scoreless relief. He had replaced starter Max Scherzer to open the sixth and induced an inning-ending double play from Jose Altuve in that frame to keep the deficit at 2-0.
The Nationals, who faced elimination five times during the postseason, added another run in the eighth and then put the game out of reach with a two-run ninth inning before closer Daniel Hudson retired the side.
The game marked the first time in any American professional sport where the road team went 7-0 in a best-of-seven games series.
“We stuck together, I know that, when we had nothing else to lose,” Nationals third baseman Anthony Rendon said postgame on Fox. “When people had written us off, we were facing elimination games that people thought we shouldn’t have been there in the first place. So we just kept on fighting and happened to come out on top.”
Nats pitcher Stephen Strasburg, whose dominant outing over more than eight innings in game six saw his side get back in the series at 3-3, and who won game two on the road in Houston, was named World Series MVP.
As was the case for most of their losses, the Astros were done in by failures with runners in scoring position.
Houston struck first against Scherzer when Yuli Gurriel homered leading off the second inning. From that point, the Astros went hitless in six plate appearances with runners in scoring position before Carlos Correa lined a two-out, two-strike single past Rendon to score Gurriel in the fifth.
The Astros finished one for eight with runners in scoring position and stranded 10 baserunners. They went four for 29 with runners in scoring position at home in the World Series.
Scherzer, who was scratched from an expected game five start due to neck and back spasms, allowed two runs on seven hits and four walks in five innings, striking out three.