Mike Napoli's majestic homer began the early breakthrough Boston needed.
Now, the Red Sox are a win away from the World Series -- with a bullpen that Miguel Cabrera and the Detroit Tigers still can't seem to solve.
Napoli opened the scoring with another big long ball, Junichi Tazawa again bested Cabrera in a crucial spot and the Red Sox edged host Detroit 4-3 on Thursday night.
Boston returns to Fenway Park with a 3-2 lead in the A.L. championship series. Game 6 is Saturday, with the Tigers' Max Scherzer facing the Red Sox's Clay Buchholz.
"Our guys are well aware of where we are," manager John Farrell said. "But at the same time the beauty of them is to not get ahead of themselves, and that will be the case once that first pitch is thrown on Saturday."
Cabrera was thrown out at the plate in the first inning, halting an early Detroit rally, and he hit into a double play against Tazawa with runners at the corners in the seventh. The Tigers scored a run on the grounder, but it was a trade-off the Red Sox were willing to make.
Napoli led off a three-run second with a drive off Anibal Sanchez into the ivy beyond the wall in center field.
Detroit's starters had allowed only three runs in 27 innings through the first four games of the series. After pitching six no-hit innings in Game 1, Sanchez allowed four -- three earned -- in six innings Thursday.
Jon Lester allowed two runs and seven hits in 51/3 innings. Boston's bullpen held on to finish off the fourth game of the series to be decided by one run.
"There's probably a reason I don't have any hair," Red Sox second baseman Dustin Pedroia said. "It's stressful."
Detroit removed banged-up catcher Alex Avila in the fourth inning because of a sprained left knee, but after the game Avila sounded confident he will be back in the lineup on Saturday.
"I should be fine," he said. "I tried to stay out there, but I just didn't have any mobility back there. It was hurting pretty good, so we decided to get me out and see how it feels in a couple days."
That is when Detroit will turn to Scherzer, a 21-game winner, to try to extend the season. The Tigers will have Justin Verlander ready to pitch Game 7 if there is one.
NLCS: For four straight starts, Michael Wacha has been all but untouchable and appeared totally oblivious to the stakes. The St. Louis Cardinals need one more just like that from the pressure-proof rookie to get to the World Series for the second time in three years.
Wacha outpitched N.L. Cy Young Award front-runner Clayton Kershaw in Game 2, and the Cardinals won 1-0 on an unearned run to take a 2-0 series lead. They're matched again in Game 6 Friday night, the precocious right-hander and the lefty who'd be at the top of anyone's list to work a must-win.
This time, the Cardinals lead the Los Angeles Dodgers 3-2.
"I just expect Michael to go out and do what he's done, just like the rest of our guys," manager Mike Matheny said. "Stick with what you've done all along the way, and don't ignore and don't deny the excitement."
The Dodgers brought the series back to St. Louis by muscling up on offense, with Adrian Gonzalez hitting two of their four homers in a 6-4 Game 5 victory Wednesday.
Dodgers manager Don Mattingly was hopeful both Hanley Ramirez (ribs) and Andre Ethier (ankle) would benefit from a travel day Thursday and be in the lineup.
Rangers: In what the team had called a retirement, Nolan Ryan said he is resigning as Texas' chief executive effective at the end of this month.
He is also selling his ownership stake in the team to co-chairmen Ray Davis and Bob Simpson.
Ryan's departure comes less than a year after ownership gave general manager Jon Daniels and chief operating officer Rick George new presidential titles and took the president's title from Ryan.
White Sox: CBSSports.com reported that Cuban slugger Jose Abreu has agreed to a six-year, $68 million contract with Chicago.
Cubs: A person familiar with the situation says Chicago is interviewing Tampa Bay Rays bench coach Dave Martinez for its manager's job.