Joshua Palacios hit a three-run homer in a seven-run fourth inning and the Chicago Cubs' postseason drive remained stalled with their sixth loss in seven games, 13-7 to the Pittsburgh Pirates on Wednesday night.

Connor Joe hit a two-run homer in the sixth as All-Star Justin Steele (16-5) lost his second straight start, allowing six runs and eight hits in three-plus innings.

Chicago (79-73), which has lost nine of 12, remained a half-game ahead of Miami (79-74) for the third NL wild card spot, with Cincinnati (79-75) another half-game back.

Steele was chased in the fourth when the Pirates hit six straight singles. All of the runners scored, with Palacios homering off José Cuas to cap the rally.

Ian Happ’s third career grand slam, a drive off Mitch Keller (13-9) in a five-run fifth, cut the deficit to 8-6. Christopher Morel started the inning with his 24th homer, a 440-drive to left that sailed to Waveland Avenue.

Joe, who had three hits, homered off Mark Leiter Jr. Jared Triolo added a solo shot for Pittsburgh.

Steele has had breakout season and is an NL Cy Young Award contender. The left-hander looked strong through the first three innings, allowing two hits and striking out six.

Then the Pirates offense broke out.

Steele has allowed 12 runs in his last two outings.

Cubs All-Star RHP Marcus Stroman said before the game he’ll gladly accept any bullpen role down the stretch.

Stroman was activated Sept. 15 after six weeks on the IL, then made a pair of scoreless relief appearances against Arizona. Those were his first bullpen outings since 2014 as a rookie with Toronto.

Stroman was 10-8 through 25 starting when he went on the IL with hip inflammation on Aug. 2. He was diagnosed with a right rib cartilage fracture on Aug. 16.

Pirates RHP Johan Oviedo (8-14, 4.27) faces Cubs RHP Kyle Hendricks (6-7, 3.77) on Thursday in the series finale.