Tigers left fielder Robbie Grossman, right, celebrates his walk-off single with first base coach Ramon Santiago after the conclusion of their game against the Kansas City Royals in Detroit on Tuesday. The Tigers won 8-7. (AP photo)

Grossman had five RBIs for the first time in his career, sending the Royals to their ninth straight loss. He ripped a two-out single off Scott Barlow (1-1) in the ninth to score Niko Goodrum.

“The heater’s going to show up at some point, I had it in the back of my mind,” Grossman said. “It showed up, and I put a decent enough swing on it to put it through.

“I’m just glad that we won this ballgame because we played good enough to win.”

The dramatic victory masked a horrendous collapse for the major league-worst Tigers, who led 7-0 with two outs in the eighth. But then Jorge Soler homered and drove in six runs over the final two innings as Kansas City rallied to spoil a great start by Matthew Boyd.

The Tigers' Robbie Grossman, left, celebrates his walk-off single with Akil Baddoo after the ninth inning against the Kansas City Royals in Detroit on Tuesday. (AP photo)

The left-hander pitched six shutout innings for Detroit, striking out five and walking two. The outing brought his ERA down to 1.94 after he exited his previous start April 29 with a left knee injury.

“He wasn’t as sharp as he’s been and yet he still threw scoreless innings,” Tigers manager A.J. Hinch said. “His effort was tremendous. He didn’t execute perfectly, but he mixed his pitches well and executed when he needed to.”

The meltdown began for the Tigers in the eighth when struggling former closer Joe Jimenez walked two batters with a seven-run lead to set up Soler’s three-run homer.

That seemed harmless enough until the ninth, when Ryan O’Hearn hit an RBI single.

Two batters later, Goodrum committed an error at shortstop on what would have been a game-ending grounder. Soler, who entered batting below .200, then drove a ball to deep center field that Akil Baddoo nearly snatched to end the game.

Instead, it went for a three-run double that tied it at 7.

Goodrum was hit by a pitch to open the bottom of the ninth and Baddoo walked, reaching base for the fifth time. Grossman pulled a 1-2 fastball through the infield to win it.