The Washington Nationals will feature in their first MLB World Series after topping the St Louis Cardinals 7-4 in Game 4 of the National League Championship Series.

Tuesday's victory over the Cardinals secured a NLCS sweep for the high-flying Nationals.

Thanks to an early surge of offense and some excellent work on the mound, the Nationals were able to see off the Cardinals 4-0.

Washington will now await the winner of the Houston Astros-New York Yankees series as they chase their title dreams.

Here are three takeaways from the Nationals' win:

Nationals got the ball rolling early

It is no secret that Washington's offense have been on fire lately, but nobody expected them to explode like they did in the first inning of this critical closeout game. The Nationals scored all seven of their runs in the first inning thanks to RBIs from Trea Turner, Anthony Rendon, Juan Soto, Victor Robles, and Yan Gomes. Then they coasted from there.

Even after amassing so many early runs, Washington kept fighting for more even though they ultimately could not add to their lead. The Nationals only struck out seven times in the contest after forcing St Louis to yank their starter Dakota Hudson after he recorded just one out.

Washington's pitching was on another level

The Nationals' starters have been phenomenal in the postseason as of late, and Patrick Corbin picked up right where Stephen Strasburg left off on Tuesday. Corbin notched 12 strikeouts through five innings just one day after Strasburg tallied 12 of his own against the Cardinals.

Corbin still gave up four runs in his showing, but Tanner Rainey, Sean Doolittle and Daniel Hudson kept St Louis scoreless for the remainder of the contest. Washington's rotation held the Cardinals to five hits in the game and only allowed them to score 1.5 runs per game in the series. Consistently being able to limit the opponent's offense made Washington's road to the World Series significantly less difficult.

Top of St Louis' order continued to struggle

The Cardinals needed big contributions from their heavy hitters to avoid elimination, and they still did not get that in Game 4 of the NLCS. The first six men in St Louis' batting order combined for three hits and 11 strikeouts. While this group did account for all four of the Cardinals' runs, three of the players were held hitless — including Paul Goldschmidt, who failed to record a hit in either of the last two games.

St Louis' top six did not capitalise on opportunities while generating nearly 70 per cent of the team's at-bats and the rest made the most of what they had. When it is all said and done, big-time players have to make big-time plays. That did not happen for the Cardinals.