A 6-3 result at Comerica Park, Detroit allowed the Tigers to celebrate their World Series berth on their home ground in front of 43,000 screaming home fans when they took an unbeatable 4-0 lead in the best of seven series against the A's.
The match was tied at 3-3 in the bottom of the ninth inning with two runners on base and two outs, when Magglio Ordonez, Tigers right-fielder, hit his second home run of the night into the stands to score the winning runs.
"I was just standing on the line, savouring the moment," Ordonez told reporters
"I knew it was gone."
Oakland shot out to a three run lead with left-fielder Jay Payton hitting a home run of his own in the fourth inning to add to the two A's runs in the first.
The Tigers rallied and were back on level terms by the end of the sixth after Ordonez's first homer and his second in the post-season.
Placido Polanco, Detroit second-baseman, was named most valuable player for the series, batting .529 after missing six weeks of the season with a shoulder injury.
"This is by far the best moment of my career," Polanco said.
"It feels great to win, to go to the World Series. We know we still have one more to go, and without a doubt, you've got to give the A's credit."
The Tigers have now won seven straight post-season games after coming from one match down to knock out the New York Yankees and now sweeping the A's, thus putting together their longest ever playoff winning streak.
Jim Leyland, Tigers manager, goes into his second World Series after coaching the Florida Marlins to the championship title in 1997.
"I think early on in spring training, we had a lot of good players. We didn't have a good team," Leyland said.
"And today I can make the statement that we've got a good team, and that's the thing I'm the proudest of."
The last time the Tigers made the World Series they swept the San Diego Padres in 1984.
Cards lead Mets
Meanwhile, the St Louis Cardinals went ahead in the National League Divisional Championship series against the New York Mets when they won game three 5-0 at Busch Stadium to take a 2-1 lead in the best of seven series.
Jeff Suppan was on fire with both
bat and ball against the Mets
Cards starting pitcher Jeff Suppan was the star of the night, throwing eight innings for just three hits and no runs, and chipped in with a home run with the bat in the second inning.
"What I think what was working was location," Suppan said of his 99-pitch performance.
"I was able to hit spots and when I missed, I didn't miss down the middle. That's key."
The right-hander's second career home run was the first Cardinals post-season homer by a pitcher since Hall of Famer Bob Gibson hit one in 1968.
"I thought it was going to be caught on the (warning) track, so I put my head down and I ran," he said.
"I was looking for someone to let me know if it was a home run. I still wasn't sure when I got to second.
"In those situations, so many times you hit a ball and it's caught on the track. So I really didn't think I hit it out. I was hoping it went out."
The Cardinals can wrap up the series if they win the next two games in St Louis, otherwise the series goes back to New York for the final two matches if required.
The winner will go on to meet the Tigers in the World Series.