Pittsburgh Pirates' Oneil Cruz (15) is greeted by Enmanuel Valdez (48) and Andrew McCutchen (22) after scoring during the third inning Monday against the Washington Nationals in Pittsburgh. Associated Press

PITTSBURGH — Oneil Cruz hit his first career grand slam to help Bailey Falter and the Pittsburgh Pirates beat the Washington Nationals 6-1 Wednesday night.

Henry Davis also connected for Pittsburgh, which had dropped four of five. Isiah Kiner-Falefa had two hits and scored run.

Falter (1-2) allowed two hits in seven scoreless innings. It was the 10th time this season a Pirates starter went six innings or more — tops in the majors.

Washington wasted a sharp performance by Mitchell Parker (2-1), who tossed six innings of one-run ball. The Nationals scored their only run on Alex Call's sacrifice fly in the ninth.

Pittsburgh jumped in front on Davis' first homer of the season — a solo shot off the foul pole in left in the fifth.

The Pirates made it 2-0 on a broken-bat groundout by Davis in the seventh, driving in Enmanuel Valdez. Third baseman Amed Rosario had to avoid Davis’ bat flying at him before he made a play to first.

The benches cleared in the seventh after a pitch by Jorge López went near Andrew McCutchen's head. López, who also hit Bryan Reynolds, was ejected.

Cruz's third homer of the season gave Pittsburgh a six-run lead.

There was a weird play in the bottom of the sixth. Tommy Pham hit a liner to left that was trapped by James Wood on a hop. Cruz went back to first not realizing what had happened, and Pham stopped running before reaching the base. Following a review, Cruz was safe and Pham was out.

Washington finished with three hits.

Nationals right-hander Trevor Williams (1-1, 7.36 ERA) faces Pirates left-hander Andrew Heaney (0-1, 3.00 ERA) on Thursday.