BOSTON >> The Boston Red Sox are going back to the World Series for the third time in 10 seasons.

Shane Victorino’s seventh-inning grand slam propelled Boston to a 5-2 victory over the Detroit Tigers tonight, clinching the AL championship series in six games and setting up a World Series rematch with the St. Louis Cardinals.

The Red Sox will host Game 1 on Wednesday night against the team they swept in 2004 to end their 86-year title drought. The Cardinals won the NL pennant on Friday night by eliminating the Los Angeles Dodgers in six games.

With 21-game winner Max Scherzer on the mound, Detroit took a 2-1 lead in the sixth inning and held it until Boston loaded the bases on a double, a walk and an error by shortstop Jose Iglesias. Then Victorino, a graduate of Maui’s St. Anthony High School, lofted an 0-2 pitch from Jose Veras over the Green Monster to set off a celebration in the Red Sox dugout and in the Fenway Park stands.

Junichi Tazawa got one out for the win, Craig Breslow pitched a scoreless eighth and Koji Uehara got the last three outs before the Red Sox poured out of the dugout to begin their now-familiar celebration on the mound.

It’s the 13th AL pennant for the Red Sox and their first since 2007, when they swept the Colorado Rockies to win it all for the second time in four seasons. Boston swept the Cardinals in ’04, winning Game 4 in St. Louis to clinch the title that put an end to generations of disappointment.

The latest trip comes one year after a last-place finish that forced the team to jettison its high-priced stars, rebuild the roster and bring in manager John Farrell. Victorino was one of the biggest additions, and he delivered today as he did for much of the season.

Scherzer got one out in the seventh but left after walking rookie Xander Bogaerts to put runners on first and second. Drew Smyly got Jacoby Ellsbury to hit a grounder up the middle, but it popped out of Iglesias’ glove behind second base and everyone was safe.

Veras came in and quickly got ahead of Victorino. But he hung a curveball and Victorino sent it toward the 37-foot left-field wall, which had already knocked down two Red Sox line drives.

This one left no doubt.

It was the second career postseason grand slam for Victorino, who also had a record-setting hit-by-pitch in the sixth.

Scherzer and Clay Buchholz also matched up in Game 2, when the Tigers right-hander took a no-hitter and a 5-0 lead into the sixth. The Red Sox rallied against the Detroit bullpen, tying it on David Ortiz’s eighth-inning grand slam and winning it in the ninth on Jarrod Saltalamacchia’s walkoff single through a drawn-in infield.

Both starters gave up hits in the first inning in the rematch, but it remained scoreless until Bogaerts doubled off the Green Monster with two outs in the fifth and scored on Ellsbury’s single.

But the Tigers took the lead on the bottom half, chasing Buchholz with a walk and Miguel Cabrera’s single before Franklin Morales walked Prince Fielder on four pitches to load the bases with nobody out.

Victor Martinez lined one high off the Green Monster to make it 2-1, holding at first with a two-run single.

Brandon Workman came in and got Jhonny Peralta to hit a hard grounder to second baseman Dustin Pedroia, who chased down Martinez in the basepath for one out and then threw home to get Fielder in a rundown. Saltalamacchia ran him back to third and dove, somersaulting over him while making the tag.

Workman struck Alex Avila out looking to end the inning.

Scherzer worked out of a jam in the bottom half after putting runners on second and third with one out. He allowed three runs on four hits and five walks, striking out seven in 6 1-3 innings.

Buchholz allowed two runs on four hits and two walks, striking out four in five-plus innings.

Scherzer walked the first two batters in the third, but Victorino popped up a bunt and Scherzer made a sliding catch for the first out.

Pedroia hit a high fly ball that was just foul of the Carlton Fisk pole above the Green Monster. After it was confirmed by replay, he hit a hard grounder down the line that Cabrera fielded, easily stepping on third base before throwing to first for the double play.