Eagles have not won a first grade premiership since 2010 before beating the reigning champions. 

Led by their own ace Tim Atherton, the Australian pitcher was dominant striking out a season-high 15 Cards' batters and scattering seven hits over eight innings of work.

Atherton also sparked his offence with his one out single to left field and was then brought in on Ben Shepard's double for Eagles' first of two runs in the fourth inning. 

A big fifth inning from Eagles scored five runs to put them in firm control of the game with hits from Shannon Crilly, Mick Shipp, Chad Blanch and doubles from Atherton and Shepard. 

For Cardinals, only Joel Thompson and Trent D'Antonio had any success, the pair hitting five of their seven hits. 

Eagles best was Ben Shepard going two from three, while Atherton, Crilly and Julian Paramanov all hit two from four.

Eagles player-coach Chad Blanch offered high praise of Atherton.

"I've never seen a team just click with one player,” he said.

“The confidence he (has) brought to the whole team has been incredible." 

Blanch also identified Ben Shepard's return to his old club during the mid-season as a vital part of their success.

At 35, Shepard was the veteran of the side but the former Australian provincial representatives' hitting and experience in the outfield gave Eagles the final piece to their premiership winning puzzle. 

Fittingly it was Shepard who made the final out of the match and another premiership to the once dominant club. 

In the lower grade grand finals, Northern Pirates continued their winning run of second grade premierships beating Shoalhaven Mariners 11-2 in a one sided result. 

Mariners were just pipped in third grade going down to Cardinals 8-5 after scores were locked 5-all going into the last inning, bringing no joy to the southerners of the competition.

Fourth grade also has a new champion after Shellharbour Warriors caused an upset over minor premiers Dapto Panthers winning 12-6. 

Panthers thumped Warriors 25-nil in the major semi two weeks earlier but could not repeat the performance when it counted. 

Panthers' miserable day continued in fifth grade after Cardinals had a huge 11-1 win while Pirates won their first sixth grade premiership in 16 years defeating Warriors 10-5.​