WASHINGTON -- Take a deep breath, Nationals fans. You’re still in good shape. Besides, you didn’t think winning a World Series would be easy, did you?

Here’s the thing: Game 4 suddenly looms large. Every World Series has a turning point, and Game 4 could be it. If the Astros win it, everything potentially changes.

The Astros picked themselves up off the mat and notched a 4-1 win in Game 3 on Friday night. They needed six pitchers to finish it and left 10 men on base. On the other hand, there’s no such thing as an ugly World Series win.

“Our pitching was phenomenal,” Astros manager AJ Hinch said. “I think we're going to be really good at taking it -- that old cliché -- one game at a time. We've been good at it.”

If the Astros win Game 4 on Saturday, they’ll become the favorites. That’s the reality for the Nationals. At least Houston will see it that way, and that’s probably enough.

The Astros will have seen a speck of light at the end of a long tunnel, and that’s a dangerous thing for a team that won its 115th game of 2019 on Friday. Only five teams in MLB history have won more in a single season.

Even when Houston lost twice at home to fall into an 0-2 hole, there was an eerie air of calm, which has to be a byproduct of three straight 100-win seasons. The Astros' confidence is virtually unshakable.

OK, here’s why Game 4 is so critical:

1. The Nationals have the pitching edge
That may not be the case again in the World Series. The Nats will start left-hander Patrick Corbin, the third of their three aces, and have their top two late-inning arms, Sean Doolittle and Daniel Hudson, with three days' rest apiece. In that way, manager Dave Martinez could not have drawn it up more perfectly.

Meanwhile, Houston will start rookie right-hander Jose Urquidy and hope for four or five innings before finishing with a parade of relievers. That could be a problem after Game 3 was also almost a bullpen game.

With starter Zack Greinke departing after 4 2/3 innings, Hinch got the final 13 outs from five relievers. He had no choice, because had the Astros lost Game 3, they would have been in a nearly impossible position.

2. One win from Houston
All the Astros wanted to do this weekend is force the series back to Houston, and they’re one win from doing that. They’re 3-1 in elimination games at home the past three seasons and had the best home record in the Majors. Yes, the Nationals have already won twice in Houston, so they know they can do it. All things considered, they would like to avoid it.

“It kind of re-establishes us in this series,” Hinch said. “They threw a big punch at the beginning of this series. Now, we've got enough experience ... that we knew we win today, get a little mojo back on our side, get a little bit of momentum.”

3. Gerrit Cole and Justin Verlander await
The Astros have their aces lined up to pitch Game 5 on Sunday night and Game 6 (if necessary) on Tuesday night. The Nats beat both those guys to open this World Series and have their own two aces, Max Scherzer and Stephen Strasburg, ready to go in Games 5 and 6. Game 7 on Wednesday night would be Greinke vs. Aníbal Sánchez, but don’t buy your popcorn just yet.

4. Doubt? What doubt?
The Astros have given the Nationals a small push in winning Game 3. To win Game 4 would create something more, and in a series Houston was heavily favored to win, there could be a significant emotional swing. It’s always unclear what that sort of thing means to a team, but the Astros would feel completely different about their chances to return to Minute Maid Park with a chance to win their second World Series in three seasons.

“We have a lot of confidence in that locker room,” Astros outfielder Michael Brantley said. “You don't win as many games as we have and gone through the tough series we have to go through to be here. We have a lot of confidence in one another, and we look forward to coming out [Saturday] and playing another good game.”

5. José Altuve’s moment
Altuve is turning this postseason into his personal showcase, and at a time when some of Houston’s other stars have been inconsistent, the face of the Astros' franchise might have been the difference between winning and losing with a pair of doubles and two runs scored in Game 3.

Altuve is the guy Houston leans on more than any of its other stars, and through the years, the great ones have risen up at the most important times. This might be one of those, as evidenced by Altuve's .400 batting average in this year's World Series.

“He’s the heart and soul of our team,” Hinch said. “He cares so much. He prides himself on what we’ve done here. He has also gotten better every year. He’s a complete professional.”