Six people were injured, including the referee, a goalkeeper, a club manager and two players from the Irish teams.
The Irish Garda said they knew of no motive for the attack, which occurred during a penalty shoot-out between Dublin Celtic and Bawnogue Boys at Clondalkin in Dublin.
The motorbike was driven on to the pitch at 1.15pm and the pillion passenger opened fire on spectators then shot indiscriminately at the players.
The identity of pair on the bike was concealed by helmets.
"It wasn't a big match or anything. It was a small district league or something like that, (with) only 100 or 200 spectators," a police spokesman said.
A schoolgirl who witnessed the attack said the pillion passenger on the "brand new, black and shiny" motorbike initially fired two shots from a shotgun.
"There were two guys on this bike. They drove on to the field, shot straight through the field, did a circle, went on round a bit further."
She said the man then shot again. "Everyone in the field just ran."
Reports from witnesses named one of the injured players as Stephen Grogan. Local milkman Rory Kelly, a spectator, was also injured.
The Bawnogue Boys' goalkeeper was hit in the leg, the match referee was wounded in the ankle and the manager of Dublin Celtic was shot. Another player, Eddie Keogh, was shot in the back, according to the schoolgirl.
Housewife Leona McGreevy was inside her house when she heard a shot fired outside.
"I just thought it was fireworks but then I came out and the road was just mad," she said. "People were running all over the place trying to find out what had happened."
Dozens of children had been playing in the road alongside the pitch, including two of her own, Denise, five, and Richard, three. "I didn't know where they were for a few minutes. All I knew was that shots had been fired."
The Garda believes both attackers were men. There are no suspects at this stage. All of the injured were adults.
A spokeswoman for St James Hospital said two men had been admitted to the casualty ward with gunshot wounds as a result of the attack but they had been stabilised.
Two men were admitted to Adelaide Meath Hospital in Tallaght. Their injuries were not serious.Reuse content