With six minutes to go in the final term and Adelaide holding onto a 16 point lead, Scott Stevens' kick inside 50 was unable to find a target and Sydney looked to rebound.
Just as a Sydney defender went to kick the Swans out of trouble Dangerfield chased and smothered the kick, with the ball spilling out and van Berlo dribbling through a goal to seal the match.
Click here to watch and vote for Dangerfield's effort
