PITTSBURGH -- The Washington Nationals clinched the National League East title and a playoff spot on Saturday night with a 6-1 win over the Pittsburgh Pirates at PNC Park.

A 10-8 loss by the New York Mets to the Philadelphia Phillies gave the Nationals the division title -- their third in five years -- outright.

Bryce Harper and Wilson Ramos each drove in two runs and reliever Reynaldo Lopez (4-3) pitched 5 1/3 scoreless innings for Washington (90-64).

The loss hurt the Pirates' dwindling chance to make it to the postseason. Pittsburgh (77-77) has won seven of its past 10 games but remains four games out of a wild-card spot, pending the result of a later San Francisco game, with eight games left.

Washington's Joe Ross was making his second start since missing 66 games because of right shoulder inflammation. He went a prescribed three innings in his first outing. However, he got yanked with two outs in the third after giving up a run and leaving the bases loaded for reliever Sean Burnett.

Ross was charged with one run and five hits in 2 2/3 innings.

For Pirates starter Ivan Nova (12-8), the honeymoon might be winding down. Since starting his Pittsburgh career 5-0 after being acquired Aug. 1 from the New York Yankees, he lost for the second start in a row.

In four innings, Nova gave up six runs (three earned) and eight hits. He also hit two batters and threw a wild pitch.

Washington scored three runs in the first inning and did it with only five official at-bats.

Trea Turner reached on a bunt single that Nova bobbled, went to third on Jayson Werth's single down the left field line and scored on Harper's sacrifice fly to make it 1-0.

Nova then hit Anthony Rendon, and Ramos got an infield single to load the bases. Stephen Drew's single up the middle scored two for a 3-0 lead.

Josh Bell's first-pitch homer to right in the third pulled the Pirates within 3-1.

The Nationals added three unearned runs in the fourth -- thanks to two Pittsburgh throwing errors -- to make it 6-1. Werth and Harper got RBIs on fielder's choices and Rendon brought home a run with a sacrifice fly.

NOTES: Washington 2B Daniel Murphy (buttocks strain) missed his sixth consecutive game. ... Nationals RHP Stephen Strasburg (elbow) played catch for the second day in a row. He had been doing that every other day lately. ... Pirates SS Jordy Mercer was out of the lineup because of a forearm injury. He was able to pinch-hit on Friday. ... Pittsburgh RF Gregory Polanco, who left in the first inning Friday because of a facial contusion, was not in the lineup. ... Pirates LF Starling Marte missed his second straight game after leaving Thursday's game because of recurring back tightness. ... As of Saturday's pregame, the Nationals had not named a starter for Sunday's series finale. RHP A.J. Cole and RHP Tanner Roark appear to be possibilities.