Accies appeared to be cruising thanks to first-half goals from Flavio Paixao and Nigel Hasselbaink, who netted his first for the club.
Jamie Hamill pulled a goal back in controversial circumstances from the penalty spot before Sammon produced the equaliser late on.
Hamilton made one change as David Buchanan was added to the side following last week's draw with Hibernian, with David Elebert named on the bench.
Kilmarnock named an unchanged side from the one that defeated Hibs in the Co-operative Insurance Cup midweek, after Frazer Wright and Mohamadou Sissoko both shrugged off knocks.
Accies could have had an early lead when Marco Paixao cut inside from the left before trying to set up Hasselbaink in front of goal but the ball was cleared for a corner, with Martin Canning then nodding over from the set-piece.
The home side had the ball in the back of the net with 14 minutes gone through Hasselbaink's header but the effort was ruled offside. However, Hamilton did take the lead a minute later.
Jim Goodwin did well to chip into the path of Flavio Paixao who directed a header past the grasp of Killie goalkeeper Cammy Bell from 12 yards.
The Portuguese could have added to his tally had he been more clinical with a point-blank shot that Bell managed to smother on this occasion, as Accies continued to pile on the pressure.
Chances had been few and far between for Kilmarnock but they could have levelled when Alexei Eremenko's cross was nodded down by Sissoko only for Wright to hook over the crossbar from a few yards out.
Instead, it was Hamilton who had the net bulging again after 38 minutes when Hasselbaink was allowed to race unchallenged from the right into the box before slotting past Bell to open his account for the club.
Kilmarnock emerged for the second half determined to haul themselves back into the game and were not too far away when Sammon slipped a pass into the path of David Silva but his shot was comfortably dealt with by goalkeeper Tomas Cerny.
At the other end, Bell was called into action when he produced a wonderful one-handed save to tip a swerving effort from Flavio Paixao just over.
Ben Gordon then came to the rescue with a clearance off the line to prevent team-mate Craig Bryson from scoring an own goal and all but snuffing out any hope of a Killie comeback.
There proved to be a dramatic climax to the match when referee Crawford Allan ruled that Simon Mensing had fouled Danny Invincibile in the area and pointed to the penalty spot.
Hamill's initial effort was blocked by the goalkeeper but the official ordered the penalty to be retaken, much to the fury of the home fans.
A delay followed as both Allan and his linesman were forced to speak to several players before Hamill converted at the second attempt with 82 minutes gone and Cerny was booked for sparking a scuffle after refusing to give Hamill the ball.
The fightback was complete two minutes from time. Rui Miguel's shot was set to fall well wide until Sammon threw himself in front of the effort and nodded into the net to claim a share of the points.