WASHINGTON >> Kurt Suzuki hit a three-run homer and the Washington Nationals beat the Chicago Cubs 9-2 in a fight-filled game Thursday night to finish a lopsided four-game sweep.

The trouble started with a testy exchange between Cubs bench coach Jamie Quirk and Nationals third base coach Bo Porter in the fifth inning. Quirk shouted from the dugout toward third base and Porter walked over to the railing, jawing and pointing his finger. 

The benches and bullpens emptied, but there was no pushing or shoving. Quirk was ejected before play resumed.

In the sixth, Chicago reliever Lendy Castillo threw his first pitch of the inning near Bryce Harper’s legs and the ball that sailed all the way to the backstop. Harper made a move toward the mound and was quickly intercepted by catcher Steve Clevenger. 

Both teams spilled onto the field again, but this time things got a little nasty.

Players pushed and shoved each other in the infield and Clevenger took an open-handed swipe at Washington shortstop Ian Desmond, who accidentally knocked down first base umpire Bill Miller while backing away.

Clevenger, Cubs right-hander Manuel Corpas and Nationals lefty Michael Gonzalez were ejected — though neither pitcher was in the game. Order was finally restored and Washington went on to its fifth straight victory and eighth in nine games.

The Nationals (85-52), who have the best record in the majors, remained 7 1/2 games ahead of second-place Atlanta in the NL East.

The Cubs (51-86) have lost 17 of their last 18 road games and six in a row overall. They were outscored 31-9 in the series.