Nicol finally disposed of the Canadian Jonathan Power, who had beaten the Scot in their last six meetings. This time, the world No 1 battled his way to victory to win 3-9, 9-2, 9-1, 2-9, 9-2.
"This is as good as winning the British Open," he beamed. "It was firstly for me, because I haven't beaten Jonathan for so long. But it was also for Scotland. It's great to get the ball rolling and I'm sure there will be more medals to follow."
There were bronze medals for England's losing semi-finalists Sue Wright and Cassie Jackman in the squash women's singles.
Reeder won gold in the floor event to add to her silver from the women's team event and immediately announced that she has decided to carry on until the Olympic Games in Sydney in two years' time.
"Annika has decided to continue, because she feels that she can still compete at the very top," John McLoughlin, the team manager, said. "Tonight's score was world class."
Reeder shocked the favourites Australia, who confidently expected a 1- 2 in the floor discipline, to retain the medal she won four years ago. Mason struck gold in the vault, with Reeder taking the bronze, her third medal of the games.
England's Andrew Atherton claimed another gymnastics medal when he added a silver in the rings discipline to the same colour he won in the men's individual all-round event. Atherton's team-mate John Smethurst won a bronze in the floor exercise.
Gault and Baxter won their second gold for England in the pairs air pistol final. Chris Hector and Kenneth Parr followed with a bronze in the men's pairs free rifle three positions event.