The Blues looked primed to snatch back-to-back wins and end their SCG hoodoo after leading at every change on Friday night.
Ultimately, though, they lost 11.12 (78) to 9.8 (62) after an Isaac Heeney-inspired fourth-quarter challenge from the Swans.
Their fourth-straight SCG defeat since 2021 leaves Carlton sitting 10th (4-6), while Sydney move to 11th (4-6) ahead of the weekend's matches.
Separated by five points at the final break, the Swans kicked five goals to two to secure the victory.
Heeney was awarded the Goodes-O'Loughlin medal as best on ground in the annual Marn Grook match, finishing with a monster haul of two goals, a career-high 38 disposals and 10 clearances.
Adam Cerra's 33 disposals effort was not enough, even with Charlie Curnow slotting three majors to reach and then surpass the 300-goal milestone.
"I guess it's stating the obvious, isn't it? They finished off the game better than us," Voss said.
"I think that's what makes you pretty pissed off, to be honest.
"We had the game where we wanted it, and we couldn't finish off the game.
"There's a set of behaviours that we obviously are not executing for long enough."
Injuries to defenders Jack Silvagni (groin) and Jordan Boyd (concussion) only compounded Carlton's woes.
Silvagni had passed a concussion test after a bump from Sydney winger Justin McInerney in the second quarter, but was eventually replaced by Boyd due to groin soreness.
Boyd then suffered a head knock in the final quarter following another bump from Joel Amartey, an incident certain to come under scrutiny from the match review officer.
Sydney also failed to finish the game unscathed, losing defender Aaron Francis to concussion in the second quarter.
Francis had lost his footing in a marking contest while attempting to limit Carlton's Harry McKay and went head-first into teammate Brodie Grundy's thigh.
The visitors had started the cleaner team with 20 inside-50s to Sydney's nine in the first quarter, but could only lead by six points at quarter-time.
Patrick Cripps, after kicking two goals in the opening term, sent a scare through the Blues camp when he limped off in the second quarter.
The two-time Brownlow medallist looked to have injured his left ankle during a marking contest with Chad Warner, but was able to return after receiving treatment on the bench.
Heeney and McInerney slotted a goal each to level the scores at 5.3 (33), before McKay (two goals) hit back to restore Carlton's lead before the main break.
After struggling to break away in a third-quarter slog, the Swans found their spark when a streaming Grundy launched the home side ahead with the first goal of the final term.
"I'm really proud of the way the players stuck to the plan, probably for the first two or three quarters," Sydney coach Dean Cox.
"We were able to really execute and play some powerful football in the back end."
13°C