Nationals 4, Padres 0: Tanner Roark retired the first 16 batters and pitched his first career shutout as host Washington defeated San Diego for the second straight day.

Roark (2-0) struck out eight and allowed three hits and one walk while improving his career record to 9-1. Padres catcher Rene Rivera broke up the perfect game with a single to center in the sixth, Jedd Gyorko singled in the seventh and Chris Denorfia singled in the ninth.

Ian Desmond went 3-for-4 with a run-scoring double and Jayson Werth had two hits for the Nationals. Adam LaRoche and Denard Span also had run-scoring hits.

Washington pushed across three runs in the first against Andrew Cashner (2-3), who allowed four runs and nine hits in six innings. LaRoche singled in the first run, Desmond smacked a double into the right-field corner and Danny Espinosa lofted a sacrifice fly to center.

The Nationals added on in the sixth when Span singled to left to score Kevin Frandsen from second. Roark gave up Denorfia’s hit with one out in the ninth before retiring Will Venable on a check-swing tapper and striking out Gyorko on his 105th and final pitch to finish his masterpiece in a time of 2 hours, 19 minutes.

GAME NOTEBOOK: Nationals OF Bryce Harper (thumb) sat out due to the injury he suffered during Friday’s game. He was scheduled to undergo an MRI exam on Saturday. … Padres OF Seth Smith (groin) missed his second straight game and is doubtful for Sunday’s series finale. … Washington had 10 hits and has racked up 43 in the first three games of the series.