CHICAGO -- The Chicago Cubs combined the long ball with pitcher Jason Hammel's effective fastball as they pulled out of a two-game slump on Friday.

Addison Russell, Kris Bryant and David Ross all homered as the Cubs (26-8) beat the Pittsburgh Pirates 9-4 in the opener of a three-game weekend series.

Hammel, meanwhile, allowed just one earned run as he worked a season-high 6 2/3 innings to improve to 5-0.

"Today, (Hammel) had command of his fastball," Cubs manager Joe Maddon said. "That's why he pitched as well and as deeply as he did. ... Fastball command was better and then the other stuff looked better because of that."

Francisco Liriano (3-2) took the loss for the Pirates (18-16), who dropped to 0-4 against the Cubs this season and slipped eight games behind Chicago in the National League Central.

"It was a good two-seamer today and I was able to get a lot of ground balls with that," Hammel said. "Keeping the ball down on a day where the wind's kind of sporadic blowing out from left to right, the best thing I could do was throw strikes that were low in the zone."

There were threats, but no scoring in a game that started out as a pitcher's duel.

The Cubs had runners at first and second with two outs before Hammel struck out to end the inning.

Hammel, in turn, struck out Starling Marte for the third out in the third after the Pirates put runners on first and second.

Chicago had runners on first and second with none out in the fourth. This time, the Cubs produced as Russell launched Liriano's 3-2 pitch to the left-field bleachers for his third homer of the season and a 3-0 lead.

The Cubs added five runs in the next inning. Bryant's sixth homer of the season made it 5-0 as he sent Liriano's 1-1 pitch to left with none out, scoring Jason Heyward.

Five batters later, Ross chased Liriano with a three-run homer to left center to open an 8-0 lead. Ross' third home run of the season plated Anthony Rizzo and Ben Zobrist with two outs.

"I left a couple pitches up, walked a guy and then get behind in a count," Liriano said. "I didn't get a pitch when I needed to and a (made) couple of mistakes."

Liriano threw 98 pitches in a 4 2/3-inning outing. He gave up eight earned runs and nine hits, walked four, struck out seven and allowed three home runs.

The Pirates got two runs back when Gregory Polanco led off the sixth with a double to right and scored when a pickoff throw sailed into center field. Francisco Cervelli's infield hit then brought home Marte to make it 8-2 with none out.

Hammel worked into the seventh, departing with two outs after walking John Jaso. He gave up two runs (one earned) and eight hits while striking out eight and walking two.

"Everything was sharper than the last time we saw him," Pirates manager Clint Hurdle said. "(Hammel) had command of four pitches today and pitched very effectively."

Hammel's previous longest outings lasted six innings on four occasions this year.

Ross singled in the eighth and scored on Dexter Fowler's two-out RBI double. Ross closed with a 3-for-4 afternoon with two runs scored and three RBI.

Andrew McCutcheon's two-run homer off reliever Trevor Cahill with two outs in the ninth -- his eighth homer of the season -- narrowed the final margin.

He said the Pirates need more than a late rallies if they hope to compete with and beat the NL Central leaders.

"It seems like they (the Cubs) are playing a lot of people tough, not just us," McCutcheon said. "We've got to key on them, we've got to jump on them."

NOTES: The Pirates still hope to reverse fortunes against the Cubs in their second series of the season. Chicago posted a three-game sweep on May 2-4 and Pittsburgh faces the same winning pitchers in the series' final two games (Jake Arrieta and Jon Lester). ... The teams play 19 times this season, returning to Wrigley Field for a three-game series beginning June 17. ... Pirates LHP Jeff Locke will make his 100th career appearance and 98th start on Saturday. ... CF Andrew McCutchen is a .340 career hitter against the Cubs in 47 career games at Wrigley Field. ... The Cubs' first losing streak of the season -- a doubleheader setback against San Diego on Wednesday -- came in their 32nd and 33rd games, the deepest Chicago has ever gone before back-to-back losses since 1907. ... The Cubs are 20-0 in RHP Jake Arrieta's starts since last season and he has a 17-0 record in that span. ... Arrieta (6-0, 1.13 ERA) goes against Locke (1-2, 4.68) in Saturday's middle game. ... CF Dexter Fowler went 1-for-4 and remains two walks away from 500 for his career.