Rapid Reaction: Royals 6, Red Sox 4

KANSAS CITY, Mo. -- One balky hamstring, one balky pitcher. Factor in a three-run homer from Billy Butler, and the result was a rough Tuesday night for Boston at Kauffman Stadium.

The Red Sox lost 6-4 to Kansas City on Butler’s eighth-inning bomb, which came off reliever Matt Albers after Daniel Bard left the game having given up back-to-back walks.

Starter Bard was called for two balks and struggled in the second inning, but had actually recovered nicely -- which added to the sour taste of the loss. He took the mound with Boston leading 4-3 in the eighth, in line for his longest outing and his third win as a starter.

Three pitches after Albers relieved Bard, however, Butler launched a 402-foot shot into the left-field fountains to put the Royals on top for good.

MIDDLEBROOKS LIMPS OFF -- Boston was already hurting after hot-hitting third baseman Will Middlebrooks left in the second inning with tightness in his left hamstring. Middlebrooks, scratched from Saturday’s lineup with the same ailment, lined an opposite-field double but hobbled slightly while advancing to third on a Marlon Byrd single. He scored on Kelly Shoppach’s blooper, and the Red Sox added another run when Danny Duffy dealt a bases-loaded walk to Dustin Pedroia. Nick Punto replaced Middlebrooks in the bottom of the inning.

BARD STILL LEARNING -- Bard’s rough second inning had little to do with Kansas City’s bats. Bard was called for a balk with runners on the corners and one out, a call he protested to home plate umpire Chris Guccione as Eric Hosmer jogged home with the Royals’ first run.

With Chris Getz still at the plate, Bard was called for another balk after stepping off the rubber and turning to second base. Getz then singled to drive home Mike Moustakas, advanced on a wild pitch and scored on a base hit from Humberto Quintero to give the Royals a 3-2 lead.

Bard rebounded, pitching into the eighth inning without yielding another run. The Royals threatened in the seventh, putting runners at second and third with one out, but Adrian Gonzalez foiled a squeeze play by fielding a bunt and firing home to get Jeff Francoeur.

Everything evaporated with one swing in the eighth, however, as Jonathan Broxton retired the Red Sox in order to record the save.