The Royals won for the seventh time in eight games and Gil Meche won his fourth straight start. Meche is 7-1 in his past 11 outings.
Soria entered the ninth with a 4-2 lead, but Coco Crisp singled. J.D. Drew struck out before Dustin Pedroia's pop fly dropped in front of left fielder Esteban German and behind shortstop Tony Pena for a hit.
"He was playing deep, and that was right between them. A blooper and nothing they could do," Soria said.
Big Papi, aka David Ortiz, rolled out to first base, and both runners were in scoring position with two outs. The crowd, heavily infiltrated with vocal Red Sox fans, geared for a frantic finish while Kevin Youkilis was walked intentionally to load the bases.
Jason Bay, the recent exchange for one Manny Ramirez, hit a hopper to the left side. Third baseman Alex Gordon and Pena bumped as both reached for the ball. No play and Bay had a RBI single.
"I should have charged it," Gordon said. "I kind of sat back on it and he was aggressive and it fell in that little spot where we both wanted to make that last out. We should have talked more, but Soria stepped up and came up big at the end."
Royals manager Trey Hillman said that Gordon should have taken over on the play.
"I think Pena may have called for that ball but, in order for us to get a play, Alex has to field that and hurriedly throw to first," Hillman said.
So Crisp was home, the Red Sox needed one run to tie and Sean Casey was at the plate. He ripped a line drive to right field that right fielder Mark Teahen caught on the run. Game over and Soria had his 32nd save.
On a steaming night, Soria made 31 pitches -- the most he's made this year in one inning -- and faced seven batters.
"That's a lot," he said. "That's a lot of work. Oh well, sometimes it happens."
Reliever Ron Mahay also had a close escape in the eighth inning. Ramon Ramirez, who replaced Meche in the seventh, got five straight outs before Casey and Jed Lowrie each rolled singles in the eighth. Mahay, a left-hander, was summoned to face switch-hitter Jason Varitek.
Mahay and Varitek are good friends, dating from their time together with the Red Sox a decade ago. Hillman reasoned that Varitek would be less menacing from the right side after batting lefty all night.
"I don't know how he's doing right-handed, but I know, against me, he's doing very well," Mahay said.
In fact, Varitek was 2-for-4 against Mahay with one home run and two walks.
"I either walk him or he gets a hit off me," Mahay said. "He's a very patient hitter against me, so I have to make some very good pitches. Being friends is also tough because bragging rights are on the line."
Mahay can brag this time. After getting in a 3-0 hole, he rebounded to strike out Varitek on fastballs and end the inning.
"Anytime you get out of a jam, it's key especially in a two-run ball game," an appreciative Meche said. "He threw some pitches to hit, and he didn't quite get them. Then he chose to pitch off the strike zone and got him."
Meche gave up two runs in the first inning, but Gordon got one back in the second with a high home run just inside the right-field pole. His 13th homer was estimated at 402 feet.
The Royals had a three-run third inning against Red Sox starter Clay Buchholz when they batted around. Three straight singles, by Mike Aviles, German and Teahen, produced one run. Later, Billy Butler had a sacrifice fly and John Buck was grazed by a pitch with the bases loaded.
That proved to be the deciding run.
Six innings later, everything came down to Soria outlasting the Red Sox. It was his game -- Hillman had no one throwing in the bullpen.
"I didn't have anybody up in that situation, because I had confidence that he'd get out of it," Hillman said.
And he did.