Brad Mills-USA TODAY Sports

Jack Suwinski hit his first career grand slam and Vince Velasquez pitched six scoreless innings as the visiting Pittsburgh Pirates swept a doubleheader from the Washington Nationals with a 16-1 win in the nightcap on Saturday.

Suwinski went 3-for-6 with a run-scoring double to finish with a career-high five RBIs, while Carlos Santana went 3-for-4 with three RBIs and two runs for the Pirates.

Miguel Andjuar hit a three-run homer, while Bryan Reynolds, Jason Delay and Ke'Bryan Hayes each had two hits and three runs for the Pirates.

Drew Maggi went 2-for-2 as a pinch hitter and collected his first career hit and RBI with a seventh-inning single for the Pirates.

Velasquez (4-2) allowed just five hits with five strikeouts and no walks in six innings for Pittsburgh, which won for the 11th time in its past 12 games to improve to a National League-best 20-8. The Pirates won the first game 6-3 on Saturday.

Leading 4-0 in the second game, the Pirates put it away with a four-run fourth inning.

After the Pirates loaded the bases with one out, Reynolds' single to right scored Tucupita Marcano, with Delay crossing the plate on Dominic Smith's fielding error to make it 6-0. Andrew McCutchen's sacrifice fly scored Hayes, and Santana's infield single that scored Reynolds pushed the advantage to 8-0.

Suwinski's grand slam off Hobie Harris in the sixth made it 12-0.

Maggi's pinch-hit single made it 13-0 in the seventh before Andujar's three-run shot pushed it to 16-0.

Nationals starter Chad Kuhl (0-2) allowed eight runs on seven hits with four strikeouts and four walks in just 3 2/3 innings.

The Pirates took a 1-0 lead in their first at-bat in the nightcap.

After Hayes led off with a double to right and took third on McCutchen's flyout to right, he crossed the plate on Santana's sacrifice fly to center.

Pittsburgh made it 2-0 in its next at-bat. Delay's sacrifice fly to center scored Connor Joe, who had drawn a leadoff walk and advanced to second on Rodolfo Castro's single before taking third on Marcano's sacrifice bunt.

The Pirates pushed their lead to 4-0 in the third, when Santana and Suwinski hit consecutive run-scoring doubles off Kuhl.

Smith went 2-for-4 with a solo homer in the ninth, while Joey Meneses also added two hits for the Nationals.

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