CHICAGO -- The hits just kept on coming.

The Chicago Cubs produced a season-high 20 hits as they beat the Pittsburgh Pirates 17-3 on Wednesday to complete a three-game sweep.

Ian Happ went 3-for-5 with a homer, four RBIs and two runs while Kyle Schwarber added a pair of two-run home runs and Anthony Rizzo hit a solo shot.

However, for Cubs manager Joe Maddon, the most impressive performance came from left-handed starter Jose Quintana, who shook off a rough first inning and then sailed to the win.

"That first inning was tough, but I thought his stuff was really good," Maddon said. "I thought the curveball was sharper, I saw a really good changeup out of him tonight also. Fastball, great life at home plate. ... Hopefully this is kind of a catapult for him."

The National League Central-leading Cubs (72-60) improved to a season-high 12 games above .500. The Pirates (63-71) fell 10 games behind the Cubs.

Quintana (5-3) worked six innings and allowed three runs and four hits while striking out nine. He threw 99 pitches, 79 for strikes, and didn't walk a batter.

"I threw too many pitches in (a two-run) first inning, but I felt pretty good out there," Quintana said. "All my stuff was really good, and I tried to recover after the first inning and tried to throw more heaters."

Ivan Nova (11-12) took his second consecutive loss and departed after three innings, his shortest outing since a 2 2/3-inning appearance on May 30 against Boston.

Chicago's Kris Bryant was 3-for-4 with two runs. Rizzo was 2-for-3 with three runs and two RBIs, hitting his 31st homer in the sixth.

Schwarber homered in the fifth and seventh innings, giving him 24 long balls for the year.

Cubs catcher Rene Rivera was 3-for-5, and Javier Baez and leadoff batter Jon Jay had two hits apiece.

"It was a rough day for us," Pirates catcher Chris Stewart said. "I'd say it was a lot of luck and some good swings mixed together. This team (the Cubs) stretches at-bats. Bryant was up there fouling everything off, and he's able to break them down and get a base hit or end up walking. Rizzo is similar. Doesn't miss pitches."

The Pirates put two runners on in the first inning and Sean Rodriguez scored on David Freese's two-out single to right center. With the bases loaded, Quintana hit Starling Marte with a pitch to bring home Andrew McCutchen and make it 2-0.

The Cubs got a run back with two outs in the bottom of the first when Happ singled in Jay, who reached on a leadoff base hit.

In the second, Baez tied the score by stealing home in a sequence that began as he reached first on a Freese error, stole second and advanced to third as Stewart's pickoff throw sailed into center field.

Baez then stole home as Quintana set up to bunt with one out. Stewart's snap throw to third was too late and Baez was already sprinting home.

In the third, Jay denied McCutchen an extra-base hit with a running, desperation grab. Jay followed with another as he nearly sprinted into the right field ivy to haul in Josh Bell's drive.

Rizzo gave the Cubs a 3-2 lead with a one-out double to deep left in the Cubs' third, driving in Bryant.

Happ then launched a towering home run off Nova deep into the right field bleachers. His 21st homer of the season brought in Rizzo for a 5-2 advantage.

Nova allowed five runs (four earned) and five hits, walked one and struck out five. He was replaced by left-hander Steven Brault for the start of the fourth.

Quintana, meanwhile, settled down after a rough start and retired the next 12 straight.

Happ struck again with a double with no outs in the fifth, driving in Bryant to make it 6-2 and start a seven-run rally.

Jason Heyward's single to right plated Rizzo for a 7-2 lead and ended Brault's night. There were still no outs when reliever A.J. Schugel gave up a double to Baez that scored Happ and Heyward for a 9-2 lead.

Quintana got in on the scoring with an RBI single that drove in Baez, and Schwarber clubbed a two-run homer to make it 12-2.

Bell hit a solo homer off Quintana to open the sixth. His 23rd homer cut the deficit to 12-3.

"Our effort's there," Pirates manager Clint Hurdle said. "We're going to regroup, and we've got an opportunity to play our best baseball at the end of the season. We've got a month of baseball left. We've played hard."

NOTES: The Pirates placed LHP Wade LeBlanc on irrevocable waivers this week, according to the Pittsburgh Tribune-Review. LeBlanc has been dealing with a left quad strain. ... Pittsburgh's Triple-A Indianapolis affiliate has clinched its fourth International League division title in six years and heads into the league playoffs next week. ... The Pirates are off Thursday and then send RHP Gerrit Cole (11-8, 3.99 ERA) against Reds RHP Luis Castillo (2-7, 3.25) on Friday in the opener of a three-game weekend series at Cincinnati. ... RHP Kyle Hendricks (5-4, 3.45) goes against Braves LHP Sean Newcomb (2-7, 4.36) to start a four-game series against Atlanta on Thursday at Wrigley Field. ... The 33 straight successful save opportunities by Cubs RHP Wade Davis in two seasons is the longest active in the majors after Baltimore LHP Zach Britton's 60-game streak ended last week.