Lightning and heavy rain suspended play on Saturday afternoon with all competitors having to finish up Sunday morning before starting the final round.
Spence, of Shorewood, Minn., was at 2-over par 218, a shot in front of Mike Small (71), Ron Philo Jr. (73) and Rich Steinmetz (73).
Because of the delay, third-round pairings were kept for the final round with players returning to the course soon after finishing.
Suzy Whaley, who became the first female PGA professional to earn a spot in the Club Pro Championship in 2002, finished the third round with an 81, falling 10 shots behind the leaders.
The top 25 finishers here will play in the PGA Championships at Baltusrol in Springfield, N.J., later this summer.