WASHINGTON — A few days later, it all seems too perfect: The Houston Astros clinched the American League pennant last Saturday with a home run in the bottom of the ninth inning by Jose Altuve, their leader and heartbeat. Minute Maid Park erupted in joy. The Astros would be hosting the opening games of the World Series for the first time, and they would have their best pitchers rested and ready.

Now, as the World Series moves to Washington for the first time in 86 years, it is the Nationals who have seized the moment, and the Astros are reeling. Houston’s aces, Gerrit Cole and Justin Verlander, lost in consecutive games for the first time all season. After a one-run loss in the opener, the Astros were humiliated in a 12-3 thrashing on Wednesday.

And the very celebration set off by Altuve’s homer turned into a shameful incident that led to the firing of Brandon Taubman, Houston’s assistant general manager, on Thursday.

In the clubhouse party after Saturday’s clincher of the A.L. Championship Series, Taubman profanely gloated — repeatedly, without prompting — to a group of female reporters about the team’s acquisition of closer Roberto Osuna, who joined the team last year while serving a 75-game suspension for domestic violence. One of the reporters is known to tweet the national domestic abuse hotline number when Osuna pitches, and was wearing a purple bracelet supporting abuse victims.