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The San Francisco 49ers and the Seattle Seahawks have an intense rivalry on the field, but fans from both sides have turned the rivalry into a friendly competition in the days leading up to the NFC Championship Game.

Leading up to the previous two meetings this season, the fans took shots at their rival. Now they are putting their money to good use.

When 49ers fans raised money to put up a billboard in Seattle back in December, the extra money that they received went to a hospital in Seattle. That's how the latest competition began, and now it will be used solely for great causes.

Both fanbases will compete to see who can raise the most money for a good cause in the rival's city. San Francisco fans, via GoFundMe.com, will be raising money for the Seattle Children's Hospital, and the proceeds from Seattle fans, via GoFundMe.com, will be donated to UCSF Benioff Children's Hospital.

Pretty awesome idea, right?

Wait—there's even more to the story. An anonymous 49ers fan has agreed to match the donations—up to $100,000—from each city and donate the money to the hospitals. The 49ers have also agreed to match the donations—also up to $100,000.

As of Thursday, Jan. 16, Seattle fans have raised more than $21,600 and San Francisco fans have contributed more than $14,100.

Fans have put their differences aside and joined forces to help out hospitals. This is why sports are so great.

Hat tip to Deadspin's Barry Petchesky for the find.