Stephen Strasburg gave up one hit and tied a career-best with 14 strikeouts in eight dominant innings, Bryce Harper hit two homers and the Washington Nationals beat the Philadelphia Phillies 4-0 on Tuesday night.

Strasburg (9-7) allowed only a single to Cody Asche leading off the bottom of the fifth -- a hard grounder to right field. He has 27 strikeouts in his last two starts.

The hard-throwing righty struck out the side twice and fanned eight of the last 12 batters he faced. He was still firing 96 mph fastballs in the eighth. Blake Treinen tossed a 1-2-3 ninth to complete the shutout.

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The Nationals have won three straight, but it's seems too late to catch the NL East-leading New York Mets.

Strasburg struck out 14 one other time in his major league debut against Pittsburgh on June 8, 2010. He had 13 in 7 1-3 innings in a loss to the Mets last Wednesday. This was his longest outing since he went eight innings in a win over Arizona on Aug. 19, 2014. Strasburg has one complete game and shutout in his career. It was against the Phillies on Aug. 11, 2013.

Harper drove one out to center field in the first for a 1-0 lead against David Buchanan (2-9). He added an RBI single in the third to make it 2-0. Harper hit an opposite-field, two-run shot to left in the eighth off Adam Loewen.

Harper finished 3 for 3 with a walk and four RBIs. He leads the NL in batting average (.338), homers (39) and runs (108).

Buchanan gave up two runs and five hits in six innings.

TRAINER'S ROOM

Nationals: INF Ryan Zimmerman (left oblique) was out of the lineup for the seventh straight game.

Phillies: 1B Ryan Howard (knee bruise) and OF Aaron Altherr (elbow bruise) were out of the lineup. Howard went to the emergency room to have his knee drained Monday night after getting hit with a throw. He could miss several games.

UP NEXT

Nationals LHP Gio Gonzalez (10-7, 3.88) and Phillies LHP Adam Morgan (5-6, 4.60) take the mound in the series finale Wednesday night.