After a rough start, Anthony Rizzo, Willson Contreras and the Chicago Cubs rebounded with an overwhelming response at the plate.

Rizzo hit a grand slam, Contreras launched two long solo homers and the Cubs kept pace in the NL wild-card race with a 17-8 win over the Pittsburgh Pirates on Friday.

Rookie Nico Hoerner hit a two-run shot for his first major league homer and had four RBIs for the Cubs, who entered tied with Milwaukee for the second NL wild card and four games behind NL Central-leading St. Louis. The Cardinals hosted the Brewers on Friday night.

Contreras, Hoerner and Nicholas Castellanos each homered in the first with the wind blowing out as Chicago scored five times, and then kept on rolling, after Pittsburgh jumped on Jon Lester for a 4-0 lead.

"Weirdly, I was expecting that response," manager Joe Maddon said. "I really thought that under the circumstances the energy level was great, then to answer as quickly as we did. I want to believe that's going to continue."

Contreras, who said he was just trying to hit pitches to right center, boosted his homer total to 23. The All-Star catcher has four home runs in six games since returning from a hamstring injury.

"I knew that we were going to have a good game,'' Contreras said. "We were hungry. It was just the first inning and we never gave up and we came back.''

Hoerner elevated a low pitch to the center field batter's eye in his first plate appearance at Wrigley Field. He drove in two more runs with a single in Chicago's seven-run fifth.

The 22-year-old infielder made his debut with the Cubs on Monday at San Diego after the team announced All-Star shortstop Javier Baez would miss the rest of the season with a hairline fracture in his left thumb. Hoerner, who played at Double-A before joining Chicago, is hitting .350 with eight RBIs through his first five games.

"To come here and contribute like he's been doing, hopefully that continues for us,'' Lester said. "He's been a little bit of a spark plug.''

Castellanos' 26th homer, a two-run shot, tied his career high and was his 15th in 40 games with Chicago since arriving at the trade deadline from Detroit. He added his 50th double to tie for the major league lead.

Pablo Reyes had a double and triple among three hits, and two RBIs. Kevin Newman had three hits and an RBI for Pittsburgh.

Lester (13-10) got the win despite allowing seven runs (four earned) on 11 hits in five innings. Alec Mills pitched the final three innings for his first save.

Pirates starter Steven Brault (4-5) was tagged for 10 runs on Chicago's five homers in 2 2/3 innings.

"Every mistake I made was a home run,'' Brault said. "It was just their day. It was a bummer, obviously.''

The Cubs returned from a 3-5 trip to open their final regular-season homestand. Following a weekend series with Pittsburgh, Cincinnati comes to Wrigley Field for three games before St. Louis visits for the final four.

Contreras homered leading off the third. After the Cubs loaded the bases against Brault, Rizzo lined a 2-1 pitch to right for his fifth career slam and a 10-4 Chicago lead.

The Pirates scored three unearned runs in the fifth. The Cubs pulled away with seven runs in the bottom of the inning when nine batters in a row reached after two were out. Jason Heyward's pinch-hit double drove in three runs.