The field again was plagued by strong winds and cold weather conditions at the three-course St. Andrews golf club in Fife, Scotland.
Sandelin's 54-hole total, 6-under 210, ties him for the lead the German Kaymer, who shot 1-over 73 at the old St. Andrews course.
Kaymer's three birdies Saturday were negated by four bogeys.
"We are playing the toughest course and it was the worst weather this week," Kaymer said, "so I think everything around par and even two or three over par is a pretty solid round today."
Sandelin and Kaymer head into Sunday's closing round with a one-stroke lead over Magnus A. Carlsson (73), who is alone in third place.
Three others, including second-round leader Markus Brier (76) of Austria and Ireland's Padraig Harrington (74), are tied for fourth place.