Matched against Royals ace James Shields, Lackey didn't have much margin for error. He exceeded that margin by allowing four runs through the opening three innings. Although Lackey came back with four shutout innings to end his afternoon, it turned out to be a moot point.
"John took an inning or two to find his rhythm and his release point," Red Sox manager John Farrell said. "Early on, he was fighting to get back in the count."
The Red Sox scored an unearned run in the first thanks to catcher Salvador Perez's throwing error, but the complexion shifted dramatically as the Royals struck back with runs in the first, second and third innings.
The tone was set immediately when Lackey walked David Lough and Eric Hosmer -- the first two hitters he faced. Billy Butler bounced into a double play, but Alex Gordon picked up Butler with an RBI single to tie the game.
The Royals took the lead in the second thanks to Mike Moustakas' leadoff double, a sacrifice and an RBI single by Jarrod Dyson. The speedy Dyson stole second and scored on Lough's broken-bat bloop single to right. When Gordon homered in the third, the Royals were up 4-1, and that proved to be all the offense they would need.
Farrell couldn't identify why Lackey had the early control issues, pointing out the veteran right-hander's pregame bullpen session was sharp.
"It was a grind early," Lackey said. "I found some things later in the game and got in a groove. But Shields was pitching well, so it was a little too late."
The series finale unfolded much like the series opener. On Thursday, Jon Lester threw 41 pitches in the first inning and allowed three runs. Although he came back with six shutout innings thereafter, the damage was done.
The Red Sox have thrived with Houdini-like comebacks all season, but not against the Royals' starters and the strong arms in Kansas City's bullpen. Boston (71-49) finished the regular season series just 2-5 versus the Royals (61-54).
"They're a pretty good team," Lackey said. "They've had some talent over here for a while. They needed some starting pitching, and they've got that now. They've always had some good arms in the bullpen and some good young talent in the lineup."
The Red Sox closed within 4-3 in the sixth when catcher Ryan Lavarnway came through with a two-out, two-run single. But Shields got through seven with the lead, and the bullpen trio of Tim Collins, Aaron Crow and closer Greg Holland sealed the deal.
A big key for Kansas City was holding down leadoff hitter and Boston catalyst Jacoby Ellsbury. One day after he had tied a career high with four hits, Ellsbury went 0-for-5 and hit into a double play. The top four in the Boston lineup combined to go 1-for-15 at the plate.
"They turned a couple of big double plays early and it's a credit to Shields for getting the ball to be hit on the ground," Farrell said.
The Red Sox are 3-4 on a road trip that will end with a three-game series in Toronto. For Kansas City, the weekend set against Boston was a confidence-booster the club hopes will propel it toward serious playoff contention.
"If you want to go to the playoffs, you have to beat playoff-caliber teams, and that's a playoff team this year," Holland said.
Shields knows the Red Sox well from his time in Tampa Bay and was in attack mode all day.
"There's a reason why they've got 70 wins," Shields said. "They work the count. You've got to attack them and get ahead." On Sunday, Shields got off to a better beginning than Lackey. That proved to be the difference.
Robert Falkoff is a contributor to MLB.com.
This story was not subject to the approval of Major League Baseball or its clubs.