Nationals 1, Diamondbacks 0: Denard Span scored on an error in the ninth inning as host Washington secured its fifth walk-off victory in the last six games.

Span singled off Arizona left-hander Oliver Perez (2-3) with one out and stole second before Anthony Rendon sent a grounder to third. Jordan Pacheco waited back on a long hop and fired the throw short, bouncing it into the stands for a two-base error that sent Span across with the lone run.

Bryce Harper, Wilson Ramos and Span each recorded two hits and Rafael Soriano (4-1) earned the win in relief for the Nationals, who matched a franchise record with their 10th straight win and remained seven games ahead of the Atlanta Braves in the National League East. Alfredo Marte and Mark Trumbo reached base twice as the Diamondbacks dropped their sixth straight.

Washington looked poised to strike in the first inning after Adam LaRoche appeared to beat out a potential double play, leaving runners at the corners, but replay overturned the safe call at first and ended the inning. The Nationals had another chance with the bases loaded in the fifth but Wade Miley struck out LaRoche on a 3-2 slider to end the inning, and Washington squandered another bases-loaded opportunity in the seventh.

Miley didn't allow a run despite giving up eight hits and issuing six walks in 6 2/3 innings. Washington starter Gio Gonzalez yielded four hits and walked three while striking out six in seven frames.

GAME NOTEBOOK: Nationals 3B Ryan Zimmerman (hamstring) resumed baseball activities Thursday by throwing, but there is no timetable for his return. … Washington OF Nate McLouth underwent season-ending shoulder surgery Thursday. … Arizona returns home to host San Diego on Friday while the Nationals host the San Francisco Giants.