Returning to the 60-over format, Colts secured a resounding win over league leaders Leschenault at the Bunbury Recreation Ground.
After winning the toss and electing to bat, Colts made the most of their home ground advantage.
Opening batsman Vikramjit Singh earned 27 runs off 49 balls early on, while Brian Hughes hit 18 off 50.
The pair were dismissed by Kurt D'Agostino (2/9 off five overs), before Paul Jones notched up 18.
With his second catch of the day, Leschenault wicketkeeper Matt Buchanan sent Jones back to the clubrooms.
The home side fell to 4/96, when Rory Given (2/23 off nine) trapped Riley Miguel (11) lbw.
Jacob Templeton (4/40 off 16) went on the attack - dismissing Colts' captain Cruize Ciallella (30), Joe Barningham (7), Ethan Kelly (7), and Travis King (1).
Saved by tailenders Jaysen Miguel (14) and Thomas Host (13), the reigning premiers reached a total of 9/177.
Following the quick dismissals of Justin Woods (10) and Matt Fink (5), D'Agostino knocked three fours on his way to 53.
Spurred on by the home crowd, Singh (6/18 off nine) ripped through the Green Caps' middle order.
The all-rounder bowled Matt Buchanan (0) and Steven Denison (1), before trapping Brody D'Agostino lbw for a duck.
Suffering a lower order collapse, the visitors were dismissed for 109.
Marist retained third spot on the Bunbury and District Cricket Association's First Grade ladder with a 28-run win over Hay Park.
Batting first at Forrest Park, Blues' opener Brayden Clarke lasted four balls before being caught for a duck.
Fellow opener Corey Fagan scored 48 runs in 62 minutes, before Cole Sawyer put up 14.
Knocking 12 fours, teammate Reece O'Connell went on to post a remarkable 82no off 126.
He and Sam Roots (50, including three fours and three sixes) guided Marist to a total of 6/125.
Hay Park opener Jono Whitney posted 89 (including 13 fours) in his two-and-a-half hours at the crease.
The Redbacks were stranded on 3/48, before Reagan Hicks (30no), Martyn Foster (23), Grant Milbanke (15) and Michael James (10) upped the run rate.
The visitors made 8/187 from its 60 overs.
Eaton, Leschenault, Colts, and Hay Park will return to the field this weekend for Round Seven.
