Rizzo’s slam among five homers as Cubs top Pirates.

CHICAGO — 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 22/3 innings.

The Cubs returned from a 3-5 trip to open their final regular-season homestand.

AP/PAUL BEATY Chicago’s Nico Hoerner watches his two-run home run Friday during the first inning of a baseball game against the Pittsburgh Pirates in Chicago.