Led by slugger Mike Napoli, the Boston Red Sox finally broke through against a Detroit starter to beat the Tigers 4-3 on Thursday and move within one victory of claiming a berth in the World Series.

The visitors seized an early 4-0 lead against Anibal Sanchez and clung on to register a victory that gave the Red Sox a 3-2 lead in the best-of-seven American League Championship Series with the series shifting to Boston for Game Six on Saturday.

"We just came out and tried to hit mistakes," said first baseman Napoli, who went 3-for-4 including a home run and a double. "It's a great team win."

The early onslaught marked a series breakthrough for Boston as the four previous starting pitching performances for Detroit had produced 42 strikeouts over a combined 27 innings with just three runs allowed on 14 hits.

Boston starter Jon Lester pitched into the sixth, giving up seven hits and three walks in allowing a pair of runs, and was credited with the win. Closer Koji Uehara, the fourth Red Sox pitcher, registered the last five outs for the save.

In Game One, Tigers starter Sanchez no-hit the Red Sox for six innings in a 1-0 victory but Boston wasted no time in piercing his aura of invincibility on Thursday.

Dustin Pedroia singled to left in the opening inning for their first hit in the series off Sanchez, and Napoli made clear it was a new day when he blasted a 445-foot home run over the centerfield fence in the second frame.

Red Sox catcher David Ross said seeing Sanchez a second time made a difference. "We get better as we see guys," said Ross. "And Napoli's home run, that was huge, getting us on the board."

Boston added two more runs in the second when doubles by rookie Xander Bogaerts and catcher David Ross, and a single by Jacoby Ellsbury followed an error at third by Miguel Cabrera as Boston took a 3-0 lead.

A wild pitch by Sanchez allowed Napoli, who had doubled, to score the fourth run of the game in the third.

"He's in one of those good streaks right now," Red Sox manager John Farrell said about Napoli, who homered in Boston's 1-0 victory over Detroit in Game Three. "He has the ability to carry us."

DOUBLE PLAYS

Detroit tallied single runs in the fifth, sixth and seventh innings but were unable to add the tying score in the final two innings as Uehara shut the door.

The Red Sox turned three double plays, including a pair of twin killings behind reliever Junichi Tazawa to defuse Detroit's rallies in the sixth and seventh.

Austin Jackson banged into a double play to end the sixth, and AL batting average champion Cabrera bounced weakly into a double dip in the seventh with men on first and third and no one out.

Catcher Ross praised the clutch pitching by the relievers.

"Uehara's our horse at the back end of the bullpen, and Taz came out and got a big double play with Cabrera up that was humongous for us," he said.

Farrell also tipped his cap to Uehara, who retired all five batters he faced. "He continues to be so efficient," the manager said. "In games here against the Tigers, it's been with his back against the wall and he's been outstanding."

The game was marked by some excellent fielding, with Tigers shortstop Jose Iglesias making a sprinting stab in short left field to rob David Ortiz of a hit, while Boston's Lester shoveled the ball on the run to first baseman Napoli to nip a bunting Iglesias in the fifth.

Detroit catcher Alex Avila left the game in the fourth with a left knee injury after a jarring collision at home plate during the Red Sox outburst in the second when Ross was thrown out trying to score from third on a grounder to second base.

Tigers manager Jim Leyland said the task ahead was simple.

"We got to win one game and then take it from there," he said.