The Boston win, coupled with the Detroit Tigers' home loss to the Kansas City Royals, sends the Red Sox to the post season for the fourth time in the last five years.
The victory also kept Boston 2.5 games ahead of the winning New York Yankees in the American League East.
Jason Varitek tied the game with a solo home run off Al Reyes leading off the ninth before Eric Hinske doubled.
After Coco Crisp popped out, Julio Lugo blasted a two-run homer to break the tie.
Jonathan Papelbon worked a perfect bottom of the ninth for his 36th save, sparking a Red Sox celebration on the field.
" It means a lot to us, just going to the playoffs," Lugo said in a television interview.
" Just getting there is the most important thing. There's a lot of tension released right now."
The Red Sox ended an 86-year drought by winning the 2004 World Series as the wild card team.
Reuters