Ian Happ's two-run home run highlighted a five-run fifth inning, and Jason Heyward added three hits and two RBIs as the Chicago Cubs belted the visiting St. Louis Cardinals 9-6 on Thursday in a battle between National League Central Division rivals.

The fifth-inning uprising made a winner out of reliever Brian Duensing (3-0), who retired the only batter he faced in the top of the frame after picking up for Chicago starter Kyle Hendricks.

Hendricks, who failed to pitch at least five innings for only the second time in his past 20 starts, surrendered three runs on nine hits in 4 2/3 innings while striking out four and walking one. He needed a season-high 113 pitches to get that far.

Pedro Strop retired the final batter of the game to earn his third save of the year.

Carlos Martinez (6-6) took the loss for the Cardinals after allowing six runs, five of them earned, on seven hits and a walk in five innings of work.

Martinez, who lost his second straight decision after winning three in a row, struck out two as the first of four St. Louis pitchers.

The Cardinals, who out-hit Chicago 15-13 in the game, scored in each of the first two innings on an RBI single by Marcell Ozuna and a solo home run by Tommy Pham, respectively. Chicago answered in the bottom of the third when Heyward singled home Victor Caratini to cut the St. Louis lead in half.

Kolten Wong's single in the top of the fifth plated Yadier Molina (who had four hits) to re-establish the Cardinals' two-run lead before the Cubs took the advantage for good in the bottom of the frame.

Anthony Rizzo's double drove home Caratini and Heyward's single an out later brought in Rizzo to tie the game. Ben Zobrist followed with a sacrifice fly that allowed Kris Bryant to touch the plate before Happ's blast over the right-center field fence pushed Chicago's lead to 6-3.

Matt Carpenter got one of those runs back in the sixth on a solo home run, but the Cubs responded again as Zobrist singled home Heyward in the seventh.

Carpenter added an RBI groundout in the eighth to cut the Cubs' lead to 7-5. Chicago answered with two runs in the bottom of the inning on run-scoring singles by Caratini and Bryant.

Wong's RBI single in the ninth ended the scoring.

--Field Level Media