The Eagles are the only professional baseball team located in the Tohoku region that was devastated by the March 11, 2011 disaster. The team's home stadium was severely damaged by the earthquake.
More than two years after the disaster that killed nearly 19,000 people, the region is still struggling and progress in recovery efforts is slow. More than 280,000 people remain living in temporary housing. Leaks of radioactive contaminated water at the crippled Fukushima nuclear plant have been keeping people on edge. Sendai is only 57 kilometers (36 miles) from Fukushima.
"This is a great present for the people of the Tohoku region," Rakuten manager Senichi Hoshino said. "I hope this victory will be an inspiration to the evacuees. There will be many tough days ahead but tonight I hope we can all enjoy this win."
The Giants are the oldest and most successful team in Japanese baseball with 22 championships while the Eagles are playing in just their ninth season in Japanese professional baseball.
After a fourth-place finish in 2012, the Eagles signed major league veteran Andruw Jones and the move proved to be a huge success. Jones hit 26 homers and drove in 94 runs as the team went 82-59 to earn its first Pacific League pennant.
Tanaka went 24-0 in the regular season. In September, he notched his 21st straight win to break Japan's previous record of 20 wins in a row set by Kazuhisa Inao in 1957.
His success this season has raised Tanaka's profile among teams in Major League Baseball, making him the most sought-after Japanese import since Yu Darvish.
According to media reports, at least seven major league teams, including the New York Yankees and Boston Red Sox, are expected to enter the Tanaka sweepstakes now that the season is over.