Kaymer had two birdies in a 1-over 73 at the 7,412-yard Carnoustie course to take the lead at 6-under 210. Sandelin later caught him with a 72.
This was the toughest day on the toughest course and it was the worst weather this week, the 23-year-old Kaymer said. You have to accept some bunkers and some bogeys.
Magnus Carlsson (73) was a stroke behind the leaders, and British Open and PGA Championship champion Padraig Harrington (74) trailed by another stroke. Harrington will be looking for his third Dunhill title in six years in the final round Sunday on The Old Course at St. Andrews.
I wouldnt see myself as favorite, he said. Im not 100 percent confident about how Im playing.
Thongchai Jaidee (72) and overnight leader Markus Brier (76) were tied with Harrington.
Five players were another shot behind, including Robert Karlsson (76) and Ross Fisher (73), who shared the lead until dropping three shots over the last four holes at Carnoustie.
Ernie Els (76) and 2005 champion Colin Montgomerie (78) missed the 54-hole cut. For Els, it was his worst finish at the Dunhill Links tournament.
The leading six and 10 of the top 11 played at Carnoustie on Saturday. Others played at The Old Course and Kingsbarns.
The first six holes into the wind claimed several victims, including Lee Westwood (76), who bogeyed the first four holes and double-bogeyed the sixth before three late birdies.
Sandelin has five wins in his career but none since 2002.
It is a long time ago that I was in the leading group on the last day, he said. These were the toughest conditions I have ever played Carnoustie in. To shoot level par makes me very happy because standing on the 10th tee I thought 2 over would be a good finish.
Harrington bogeyed four of the first six but made birdies at Nos. 12 and 15.
I hit a drive about 195 yards on one hole and had three three-putts in the first six, Harrington said. In these conditions, you have to play sensible shots all the time. Its about hitting it in the right place. I got caught once or twice going for pins.