The teenager blasted a classy 129 not out from 192 deliveries in his side's Clyde Young Shield encounter against the Lodgers, as the Cats finished with 8-251 off 80 overs.
After winning the toss and electing to bat, Mooroopna was quickly in trouble at 2-26 due to Pine Lodge's Sam Hayes (1-29) dismissing openers Josh Catalano (run out for eight) and Brad Boyle (bowled for 14).
With his side 2-26, Carn put value on his wicket and nestled down to score a brilliant century that included 11 boundaries and one maximum.
Saturday's performance eclipsed his previous best score of 92 and it was his first century.
In other games, Undera locked in first innings points against Numurkah after a classy five-wicket effort from evergreen Glenn Campbell.
The Undera bowler ripped through the home side's batting line-up with damaging figures of 5-32 off 22.5 overs.
Campbell's efforts, along with John Valentin (3-8), rolled the Blues for a miserly 81.
In reply, Undera finished the day 6-102, with Bayden Bailey not out on 58.
Elsewhere, ladder leader Kyabram will face an uphill battle on Saturday in its run chase against Tatura.
The Bulldogs posted 247 off the back of a sublime half-century from youngster Harry Murdoch, who finished on 81 not out.
Murdoch's effort with the bat was matched by Kyabram's Connor Hawes’ five-wicket haul with the ball.
Meanwhile, Karramomus posted a commanding 251 against Euroa at Vibert Reserve, with Tim Kelly's 78 the standout effort.
And Preston Hall was the saviour for Northerners against Waaia, with his 83 guiding the Jets to 243.
Waaia will resume on day two at 1-16 off 10 overs.
Lastly, Katandra is in dire straits against Shepparton United, with the Eagles stranded at 3-7 in reply to United's 196.
And thanks to Tom Janke's important 49 not out, Old Students will be defending 233 next week against Central Park-St Brendan's.