In the bottom of the seventh, the crowd rose to its feet as Julio Lugo reached base with his third hit of the night, a double off the Green Monster, and Pedroia turned a 1-2 count into an eight-pitch walk.
David Ortiz stepped to the plate. But when he launched the ball up the chute to left-center, a high fly that had the carry -- if not the distance -- of an opposite-field home run, Kansas City outfielder Emil Brown leapt high, his back against the Monster. He snared the ball, then fired to the cutoff, who doubled Pedroia off first base to end the inning.
"It looked like it was getting off the wall," Pedroia said. "So I went."
Pitcher Leo Nunez earned the first start of his career, but not the win, because he failed to throw the minimum five innings for a decision.
The 23-year-old made it through the Boston lineup unscathed twice, but lacking the stamina of a starter, Nunez left after throwing 74 pitches. A collection of fire-balling Royals relievers took care of the rest, allowing two runs over five strong innings.
"You don't expect to use five [pitchers] in a 9-3 game," Kansas City manager Buddy Bell said. "But we pretty much understood we needed to do that before the game anyway."
Reliever Jimmy Gobble, the pitcher of record, yielded to Royals righty Zack Greinke in the fifth. Greinke looked strong against the Red Sox as a starting pitcher on April 5, but he lost his rotation spot in early May.
On Tuesday, Greinke shepherded Kansas City into the seventh while throwing 97-mph fastballs.
"As a starter he was nowhere near that," Mike Lowell said.
The Red Sox pushed across two runs against Royals righty Joel Peralta in the eighth inning, but Joakim Soria shut the door on the rally, running his personal scoreless streak to 18 innings while striking out three batters.
"They've got some good arms," Lowell said. "They're not someone to be taken lightly."
It all unraveled for Red Sox starter Tim Wakefield and reliever Javier Lopez in the seventh after the first three Royals reached safely on hard hits, starting with a double by Reggie Sanders and ending with a two-bagger by John Buck.
Red Sox manager Terry Francona pulled Wakefield after inducing a groundout to Kansas City shortstop Tony Pena, but Lopez walked the left-handed-hitting David DeJesus. By the end of the seventh inning, the Royals had scored two more runs, opening up a 8-1 lead.
The Red Sox have alternated wins with losses in all six games since the All-Star break. During that stretch, they have averaged just more than four runs as a team.
"If we knew the solution, we'd probably look for a different result," Lowell said. "But it's not lack of effort. I think in the course of a long season you're going to run into stretches where things aren't working out.
"We lost the ballgame," he said. "I don't think it's a major catastrophe. We'll got out tomorrow, hopefully win the series, and look forward to playing the White Sox."