PITTSBURGH — Mark Melancon knows the fastball that made him an All-Star two years ago is off a bit. He’s just not worried about it. At least, not yet.

Might be time to start.

The Chicago Cubs touched Melancon for three runs in the ninth inning on Tuesday night to rally for a 9-8 victory. Melancon (0-1) surrendered a leadoff single to Anthony Rizzo, a double to Jorge Soler and walked Kris Bryant before giving up a game-tying two-run single to Starlin Castro. Wellington Castillo followed with an RBI groundout as the Cubs won their second game when trailing heading into the ninth this season.

“What is the drop in velocity?” Melancon asked. “I don’t pay attention to that. I’m worried about results.”

At the moment, they’re not so hot. Melancon’s ERA ballooned to 8.53 after his first blown save. He’s given up nine hits and allowed 12 baserunners in just 6 1-3 innings so far.

“I like when teams are aggressive,” Melancon said. “I think that only helps me normally but you get a night like tonight where two pitches you’ve got a guy on second and third. That’s part of it. That’s part of throwing strikes and going after guys, which is what I do.”

Castro finished 3 for 5 with 4 RBIs. Edwin Jackson (1-0) picked up the victory in relief. Hector Rondon worked a perfect ninth for his third save.

Chicago rookie Addison Russell went 0 for 5 with three strikeouts in his major league debut. The club called the highly touted 21-year-old infielder from Triple-A earlier in the day.

Pittsburgh’s Jung Ho Kang went 2 for 4 with a bases-clearing double in the seventh for the first RBIs of his career. Starling Marte hit his fifth homer of the season for the Pirates. Josh Harrison led off the bottom of the first with his second home run and Francisco Cervelli added two hits and two RBIs.

The Pirates appeared to finally take control when Kang, a 27-year-old infielder who is the first position player to jump from the Korean Baseball Organization directly to the majors, smacked a double to center off Jason Motte to put Pittsburgh in front 8-5.

It was a breakthrough moment for Kang, who hit .356 with 40 home runs in the KBO last season. Playing time has been hard to come by, though general manager Neal Huntington insisted over the weekend that Kang was better served getting spot duty in the majors than regular at bats in Triple-A.

The Cubs walked Marte intentionally in the seventh to get to Kang, who sent the ball to the wall.

“I felt like it was an opportunity to prove myself and show who I am,” said Kang.

Pirates manager Clint Hurdle believes the hit — and the standing ovation that followed — will put Kang at ease as he continues his transition.