WASHINGTON -- Bryce Harper is very close to his father, Ron, who taught him the game and a strong work ethic while the slugger grew up in Las Vegas.

So it was a special moment when the Washington Nationals right fielder hit a home run in the first inning on Sunday -- Father's Day -- during a nine-run first frame for the Nationals.

"It is awesome, a very cool moment," said Harper, who homered for the second day in a row after sitting out Friday with a light left hamstring strain.

Harper's 24th home run of the season gave the Nationals a 2-0 lead and sent Washington on its way to a 9-2 victory and a series sweep of the Pittsburgh Pirates.

"He hit the ball in the second deck," marveled Clint Hurdle, the Pittsburgh manager.

"We had some balls fall and really capitalized on everything we could. We had a great weekend and hopefully we can stay in first place," Harper added.

Third baseman Yunel Escobar (two hits) also homered in the first -- a three-run shot -- as Washington sent 12 batters to the plate.

Washington had rookie pitcher Joe Ross fan 11 batters Friday, saw Max Scherzer throw a no-hitter on Saturday and had Gio Gonzalez (5-4) pitch seven scoreless innings Sunday. So can the Nationals build on the three-game streak?

"We won today. That is all we care about," said Washington manager Matt Williams.

The Pirates entered the series with eight wins in a row but were outscored 19-3 in the three games against Washington. Starter Charlie Morton (5-1) gave up all nine runs in the first -- a franchise record for Washington -- and left after retiring just two batters.

The last time Pittsburgh gave up nine runs in the first inning, according to Elias, was on June 12, 1953, against the Milwaukee Braves, when it allowed 10 in the second game of a doubleheader.

"Kick it to the curb," Hurdle said, when asked what Morton can take from the start. "The facts are we missed spots. The inning went sideways; it happens. They are an aggressive-swinging team. They had two homers for five runs. They found grass (with hits). They put up nine. That is a big deficit to overcome."

The Nationals pitching staff set a franchise record with 24 scoreless innings before Pirates first baseman Corey Hart hit a two-run homer in the ninth off Felipe Rivero.

"It is not hard; there is not a lot of hard contact," said Washington first baseman Clint Robinson, when asked about what it has been like to play defense this series. "We are going to win a lot of ballgames when they do that."

Gonzalez, who gave up five runs in his last start, allowed just four hits and no runs in seven innings before Matt Thornton took over in the eighth. First-place Washington (37-33) has won seven in a row over the second-place Pirates (39-30).

The Nationals' 12-hit attack was also aided by a two-hit effort from catcher Jose Lobaton and starting left fielder Michael A. Taylor.

Vance Worley took over for Morton in the first and pitched 4 1/3 innings of scoreless relief, allowing just two hits to help save the Pittsburgh bullpen.

Lobaton and Taylor had RBI singles to make it 4-0 in the first after the Harper homer. Shortstop Ian Desmond scored on a wild pitch, and Gonzalez had an RBI double down the right-field line to up the margin to 6-0.

Escobar then crushed a three-run homer down the left-field line to make it 9-0 and send Morton to the showers.

By the second inning, every Washington starter had reached base.

The Pirates got a double in the first inning by center fielder Andrew McCutchen with two outs. Second baseman Josh Harrison, who made the last out in the no-hitter, had two hits Sunday.

NOTES: The no-hitter by Washington RHP Max Scherzer on Saturday meant he was the first pitcher to throw back-to-back complete games while allowing one hit or less in both games since Jim Tobin in 1944 with the Boston Braves, according to ESPN Stats and Information. Scherzer threw a one-hitter at Milwaukee on June 14. ... Washington OF Bryce Harper, who hit a home run Saturday, was in the lineup again Sunday after he sat out Friday with a mild left hamstring strain. ... The Nationals activated RHP Tanner Roark from the paternity list and sent RHP Taylor Hill to Triple-A Syracuse. ... After an off day Monday, Pittsburgh LHP Jeff Locke (4-3, 4.74 ERA) will face Cincinnati RHP Johnny Cueto (4-4, 2.98 ERA) on Tuesday. ... The Nationals are off Monday and begin a series with Atlanta at home Tuesday as LHP Alex Wood (4-4, 3.40 ERA) pitches for the Braves. Washington had not named its starter for Tuesday.