CHICAGO (AP) -- Anthony Rizzo hit a grand slam, Willson Contreras launched two long solo homers and the Chicago 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.
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 be out of the season with a hairline fracture in his left thumb.
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.
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 led off the third with his 23rd homer, to the batter's eye. 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, set up when catcher Contreras threw Adam Frazier's tapper in front of the plate wide of first with two outs.
The Cubs pulled away with seven runs in the fifth when nine batters in a row reached after two were out. Jason Heyward's pinch-hit double drove in three runs.
FRUSTRATED AND UPTIGHT
Cubs president of baseball operations Theo Epstein called his team's performance on its recent trip "uninspired" and "unacceptable" in radio appearance on Thursday. Before Friday's game, Epstein softened his tone and emphasized that no one was "being put on notice."
"I think everyone around the team is frustrated because we're not doing what we need to do," Epstein said. "I think we all feel this is a team that should be winning."
Manager Joe Maddon said his team was playing "tight," despite a roster loaded with players who have winning postseason experience.
"When you play uptight, it's very difficult," Maddon said. "Our guys care too much, that's my interpretation. I want us to loosen up and play baseball.
"I think if we're able to do that over the next two weeks, we'll get the results we're looking for."
Pirates: CF Starling Marte was out of the lineup for a fifth straight game with a left wrist sprain he suffered while making a sliding catch on Sunday against St. Louis. ... The Pirates claimed LHP Williams Jerez off waivers from San Francisco and placed RHP Kyle Crick on the 60-day injured list. Crick needed surgery on his right index finger after a clubhouse fight with fellow reliever Felipe Vazquez.
Cubs: RHP Craig Kimbrel, on the IL with right elbow inflammation, threw a 24-pitch bullpen session on Thursday. Epstein said Kimbrel would toss another session on Sunday, but said there's no timetable for his return.
Pirates RHP James Marvel (0-1, 3.60 ERA) makes his second major league start when he faces RHP Kyle Hendricks (10-9, 3.33) on Saturday. Marvel allowed two runs in five innings in his debut against St. Louis last Sunday. Hendricks is 2-0 with a 2.67 ERA in his last five starts.