Published Wednesday, 17 October 2012
Aisling Reilly faced her club colleague in the handball final. (© Hoganstand)
Shannon, who is a three-time world champion as well as the defending champion, started well and won the first game 21-9.
But Reilly fought back to win the second 21-6 game and held on to win the tie-break round 11-5.
The pair from St Paul's in west Belfast had already met twice this year with 22-year-old Reilly coming out on top on both occasions.
And their meeting in Dublin was not the first time they had clashed in a world final. They faced each other in Portland, Oregon, in 2009, in which 33-year-old Shannon won the title.
Cavan man Paul Brady made it an Ulster double as he retained the Men's World title by defeating American Luis Moreno.
Ulster GAA President Aogán Ó Fearghail congratulated the handballers.
"I am a very proud Ulster man and a very proud Cavan man after watching Paul Brady play his heart and soul out to win his fourth World Title," he said.
"I am so proud of Paul Brady and he will be the pride and joy of Cavan, Ulster and indeed Ireland."
"I also warmly congratulate Aisling O'Reilly who won the women's World Title after defeating her fellow County player Fiona Shannon. It says a lot for handball in Ulster that the women's decider was between two Antrim women."
"We look forward to welcoming Paul and Aisling with the World Titles back to Ulster."
The next World Championships will be in Calgary, Canada, in 2015.