Colin Moran had three hits for the Pirates, who still have lost nine of 12 games and dropped back-to-back series against National League Central rivals during a six-game homestand.

Jason Heyward had three hits for Chicago, which had won three in a row and four of five.

Pirates right-hander Joe Musgrove (2-0), making his second start after beginning the season on the disabled list, gave up one run and seven hits in seven innings, with five strikeouts and four walks. He also had a hit for the second time in his two games.

Pittsburgh closer Felipe Vazquez, who had failed to convert on his past three save opportunities, gave up two hits in a scoreless ninth for his 10th save.

Kyle Hendricks (4-4) pitched five strong innings for Chicago, allowing two runs and seven hits, with one strikeout and one walk. He has allowed three or fewer earned runs in each of his past nine starts dating to April 12.

The Cubs took a quick 1-0 lead after Albert Almora Jr. opened the game with a double to left-center. Javier Baez followed with a single to bring home Almora.

Pittsburgh tied it in the bottom of the first when Harrison hit his sixth career leadoff homer, to right. It was his second this season.

In the second, the Pirates' Corey Dickerson stretched a hit to the corner in left into a triple, putting him in position an out later to score on Gregory Polanco's sacrifice fly for a 2-1 lead.

The benches and bullpens emptied in the third. Musgrove led off with a single, and on Harrison's subsequent grounder, Baez, the pivot at second, took exception to Musgrove's slide to break up a double play.

Baez barked heatedly at Musgrove, and all the players poured onto the field. There were no punches thrown or pushes.

--Field Level Media