That was almost the sum total of the Italian international's contribution, although it was from his first-half corner that Andy Linighan got in a header that bounced clear off the bottom of Sullivan's right-hand post.
One moment that did lift the spirits in the first half was Sullivan's splendid save in the 20th minute, arching backwards to tip Paul Warhurst's lob over his crossbar. It did not get any better after the interval, despite Ceri Hughes thumping a 25-yard volley inches the wrong side of Kevin Miller's post.
Alan Kimble did slice an opening for Carol Cort in the 66th minute, but the Dons striker turned inside David Tuttle only to be crowded out. The Palace defender crumpled after his challenge and waved for assistance. He was was carried off to be replaced by Marc Edworthy.
When they went behind, Wimbledon decided they needed to replace the weapon that had been firing blanks for 80 minutes, so Andy Clarke and Dean Holdsworth replaced Efan Ekoku and Cort for a last charge.
Holdsworth created the Dons' clearest chance, minutes from time, with a neat nod down to Stewart Castledine's feet, but Miller got his body in the way of the fiercely struck shot. Yet the game ended with Chris Perry, at the other end, getting a desperate boot to Palace substitute Neil Shipperley's shot.
Afterwards Wimbledon manager Joe Kinnear said of Marcus Gayle, who went off after 37 minutes: "He may have a virus. He was finding it extremely hard to breath when he stretched his legs."
On the decisive goal, Kinnear added: "If the keeper calls for it he has got to make sure he hold on to it. We have been punished for sloppy of defending."
The Palace manager Steve Coppell reported that Tuttle, who may have broken a leg, was going to be X-rayed.