WASHINGTON — It is not fair to say the Nationals have let the Astros off the canvas, because that would be shortchanging Jose Altuve and the rest of the AL champs.

What wouldn’t be wrong is the feeling that the World Series underwent a major change Saturday night when Alex Bregman’s bat came alive in Game 4 and helped carry the Astros to an easy 8-1 victory in front of 43,889 at Nationals Park on Saturday night.

After losing the first two games at home, the Astros evened the Series, 2-2, heading into Game 5 on Sunday night in the nation’s capital that is expected to be watched from a suite by President Trump.

Game 5 will be highlighted by the Astros starting Gerrit Cole and the Nationals countering with Max Scherzer. It is a rematch of Game 1, which the Nationals won, 5-4. Game 6 on Tuesday in Houston will feature Justin Verlander facing Stephen Strasburg.

Bregman, the Astros’ MVP candidate, started the night hitting .077 (1-for-13) in three World Series games and batting .208 (10-for-48) in 14 postseason games. By the time the third baseman was done assaulting Nationals pitchers, he had a grand slam, five RBIs and three hits.

“We stopped the bleeding [Friday] night and then came out and played well again [Saturday]. We want to just keep it rolling,’’ Bregman said. “We’re fired up. This is why you play the game. This is the World Series.’’

Altuve has played long enough with Bregman to understand the valleys can be replaced by peaks quickly.

“I wasn’t worried about Alex,’’ said Altuve, whose sensational postseason continued with two hits and a run scored. “He can go 0-for-10 then 10-for-20 with 20 RBIs.’’

Each team has won twice in the other’s ballpark, which means the Series has gone from best-of-seven to best-of-three, and two of those games are scheduled for Minute Maid Park in Houston.

“Tonight was a wake-up call. We realized we can put up crooked numbers quick,’’ Josh Reddick said of the Astros scoring twice in the first and two more in the fourth against Patrick Corbin.

Though Corbin didn’t get much support from a lineup that was held to a run, four hits and went 1-for-9 (1-for-19 in the past two games) with runners in scoring position and stranded nine, credit has to go to Jose Urquidy, a 24-year-old right-hander who made nine big league appearances during the regular season. He blanked the Nationals for five innings, giving up two hits and striking out four.

“What a night. He was unhittable,’’ Altuve said of Urquidy, who was followed by five relievers who allowed a run in four innings.

Urquidy is the third Mexican-born pitcher to post a win in a World Series game. Aurelio Lopez and Fernando Valenzuela are the others.

“It’s a seven-game series. We have a good vibe about us. We haven’t changed a bit. This is the same team that won 100-plus games. This is the same team that won the division, won two playoff series,’’ Astros manager A.J. Hinch said. “There was a lot of noise around losing the first two games, and rightfully so because the Nats had outplayed us, like I said. And I think we turned it around and now we’ve outplayed them for a couple of games, and now we have a three-game series, the winner of two of three wins the World Series.’’

Did the Nationals get Bregman going? Or was it a matter of time before he got hot? That can’t be answered until Game 5 is dissected, but the biggest sin the Nationals might have committed in the World Series is allowing Bregman to get hot because he is capable of carrying a team, especially when there are just three more games left in the season.