The scoreboard said best and most succinctly when the game was over: "Nats Clinch".

The Washington Nationals completed a franchise turnaround that started a few years ago, defeating the Los Angeles Dodgers 4-1 on Thursday night to clinch a postseason spot for the first time.

With 91 wins on the season, the Nationals will at least finish with a wild-card spot, but will most likely win the National League East division. The team has a 5 ½ game lead over the Atlanta Braves.

It's the first time a team in Washington will make the postseason since the Senators did in 1933. The Nationals have never finished better than third place in the division or had a winning season in Washington. In 2008 and 2009 the team lost 100 games.

''That was fun, but it's not what I had my eye on,'' manager Davey Johnson told the Associated Press. ''I don't want this.''

Washington was fueled by a strong start from Ross Detwiler and an RBI double from third baseman Ryan Zimmerman, who has played with the Nationals since they first moved to Washington from Montreal in 2005. The last time the Expos made the playoffs was in 1981.

"We've been through a lot and a lot of us in here have been through a lot of not-good times and these are the beginning of hope for a lot of good times," Zimmerman said. "It's a first step, and it's a long ways to go."

The sellout crowd of over 30,000 cheered loudly as the team closed out the game.

"I noticed like in the fifth or sixth, some signs, some different things that kind of keyed me into that this wasn't going to be an ordinary evening," Jayson Werth said.

"That was not an ordinary win."

The Nationals joined the Cincinnati Reds as the first two teams to clinch postseason spots.

Washington got out to an early lead off Zimmerman's double in the third, which scored rookie Bryce Harper. Zimmerman came around to score on a wild pitch later in the inning for a 2-0 lead. That was all the Nationals would need.

In the fourth Detwiler gave up a solo home run to Mark Ellis, but that was his only blemish on the day. Detwiler pitched six strong innings, gave up only three hits and struck out five.

The Washington bullpen was stellar following Detwiler, giving up only one hit over the last three innings while also striking out five.

Drew Storen closed out the game in ninth by striking out Hanley Ramirez for his third save of the season.

Harper, Washington's exciting rookie, didn't even realize the team had clinched until after the game.

"Everyone's going crazy. I looked at the fireworks and I go: 'I guess we just did something.' Then somebody handed me the playoff shirt and playoff hat and I said, 'Well, I guess we're going to the playoffs,'" Harper said.

The loss put the Dodgers in a tough spot if they want to make the postseason. They are now three games behind St. Louis for the wild-card and have lost 10 of the last 14 games.

"You know, honestly, it does (feel like our chances dimmed). It feels like it is a little bit, and I don't think there's any way for us to look at it other than that," said manager Don Mattingly. "I mean, it's, yeah, we're going the wrong direction.

Chris Capuano pitched for the Dodgers and lasted five innings, giving up three earned runs and six hits.

"For us at this point, we're going to have to put a run together that's going to be more than just win a series," said Mattingly.

The last time the city of Washington tasted the playoffs was 79 years ago when the team had a player-manager in Joe Cronin. That team eventually made it to the World Series before losing to the New York Giants in five games.

Washington manager Davey Johnson summed it up best when thinking about the past. "I can't remember that year," Johnson said with a laugh.

Luckily for the Nationals, they have a playoff future to look forward to.