Clarke failed to make the cut at last week's 149th Open at Royal St. George's, but he got off to a quick start at the Sunningdale Old Course in Berkshire, England, making four birdies on the front nine before adding two more birdies and bogey on his way back to the clubhouse. A win for the 2011 Open champion this week would mark his first Senior Major Championship victory.
"I think you've got to respect Sunningdale," Clarke said in his post-round interview. "You've got to play smart here. It's important to hit it on the fairways, that can be any week, but I've played here enough to know that there's certain flags that you go for and there's certain flags that you don't go for.
"And I played smart around here. I hit away from the flags to the middle of the greens and gave myself some chances, and kept giving myself chances there in the last few holes. Didn't make anything at the end but just played smart. I think the winner is going to have to play smart this week."
Kingston, who won the Senior Open Invitational in Germany last week, took a share of the lead after carding four bogeys without loss.
Elsewhere, Germany's Bernhard Langer headlines a small group of three players on shot back, tied-second place.
Four-time major winner Ernie Els also had a solid opening day, carding a 3-under-par 67.