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The Washington Nationals' only RBI came on a ball that traveled 30 feet.

Miami pitching has sent the Nats' bats into a slump, and as a result, first-place Washington is in danger of being swept. The Nationals managed only five hits Tuesday and lost to the Marlins 3-1.

Washington came to Miami after sweeping a series at Atlanta, but in two games the Nationals have totaled four runs and 12 hits while going 1 for 12 with runners in scoring position. They have scored nine runs in four games this season against the Marlins and have never beaten Josh Johnson, who pitches against them in the series finale Wednesday.

The Nationals' only run Tuesday scored on a squeeze play by Corey Brown, starting for the first time this season after joining the team from Triple-A Syracuse on Monday.

Why bunt then?

"We were pounding the ball," manager Davey Johnson said jokingly.

They had another scoring chance trailing 2-1 in the eighth. Steve Cishek walked consecutive batters to load the bases, but Bryce Harper struck out and Ryan Zimmerman grounded out.

"We had them in the spot where we should score a run," Johnson said. "We had the right guys up. It just didn't happen. It's frustrating, but that's baseball."

The National went 0 for 5 with runners in scoring position.

Edwin Jackson (1-3) allowed only two runs, one earned, in 6 2-3 innings. He is 0-3 in his past eight starts even though his ERA this season is only 3.17.

"You can't do much better than he did," Johnson said.

Anibal Sanchez allowed only an unearned run in seven innings to remain unbeaten in 19 starts against Washington, and the Marlins broke the franchise record for victories in a month. They are 20-8 since May 1, best in the majors.

"I want 20 wins every month," manager Ozzie Guillen said. The Marlins climbed six games above .500 for the first time since last June 4.

Greg Dobbs, pinch-hitting for Sanchez, drove in the run that put Miami ahead to stay with a sacrifice fly in the seventh. Hanley Ramirez hit his eighth homer leading off the eighth.

Sanchez (3-3), plagued by poor run support all season, this time received enough to snap a streak of losses in three consecutive starts. He improved to 8-0 against Washington with a 1.97 ERA.

Sanchez allowed only three hits and one walk and lowered his ERA to 2.56.

Pinch-hitter Jhonatan Solano, making his major league debut, doubled with two outs in the ninth before Heath Bell earned his ninth save in 13 chances.

Miami broke a 1-all tie with an unearned run in the seventh. Chris Coghlan singled and went to third when Jackson made a wild pickoff throw, and Dobbs brought the run home.

"It was a well-pitched ballgame on both parts," Jackson said. "It's who can make the least amount of mistakes, and they capitalized on that mistake."

The Marlins had only one hit until the sixth, when they scored on a double by Omar Infante and a two-out RBI double by Giancarlo Stanton to make it 1-all.

Ian Desmond, who grounded out on the 10th pitch he saw in his first at-bat, singled for the Nationals' first hit to start the fifth. He stole second and continued to third when the throw was errant. When he broke for home on a 1-1 pitch, Brown laid down a bunt that left the Marlins without a play at the plate.

"It was good time in the game" for a bunt, Desmond said. "Anibal obviously is a tough opposition. You have to take them when you get them."

Harper tripled with two outs in the sixth, but Zimmerman grounded out to end the inning. Harper is batting .400 during a nine-game hitting streak that has hiked his average to .284.

Notes: The Nationals accepted the contract of OF Erik Komatsu, who was assigned to Triple-A Syracuse. ... The Nationals recalled Solano nine days after his brother Donovan broke into the majors with the Marlins. Their parents flew Tuesday from Colombia to attend the game, and didn't seem to mind that neither son was in the starting lineup. Mom wore a Marlins jersey, and Dad wore a Nationals jersey. ... Washington C Jesus Flores (right hamstring) will likely sit out at least another game or two, Davey Johnson said. ... Josh Johnson is 7-0 in 14 starts against the Nationals with a 3.22 ERA. RHP Chien-Ming Wang makes his first start of the season for Washington.