For the second day in a row, the 56-year-old South Africa native produced a bogey-free round.
"Well, that's never a goal of mine, to keep a clean scorecard, it just happened that way," Els said. "But it's nice, means I'm playing solid."
South Korea's Y.E. Yang and Germany's Bernhard Langer also posted 67s to stay within two strokes of Els. South Africa's Retief Goosen (68) and first-round co-leader Justin Leonard (70) are another shot behind as 17 of the top 18 in the standings through 36 holes broke par on a picturesque Saturday.
"Just a joy," Els said. "I mean, the golf course is just so pure. The weather conditions have been just absolutely fabulous. Tomorrow we're getting a little bit more breeze, it's going to be a little bit more challenging."
Langer, who has two Dominion Energy titles on his resume, will play with Els in Sunday's final group after shrugging off a triple-bogey 6 at No. 14 to finish with four straight birdies.
"It was a triple bogey and it wasn't even a bad shot," Langer said. "Yeah, pretty weird but it happens, I guess. Think you've seen it all and then something else comes up."
Argentina's Ricardo Gonzalez delivered the day's finest round - a 7-under 65 that featured nine birdies and two bogeys - to climb 34 spots in the standings. He sits four shots behind Els along with Canada's Mike Weir, Denmark's Thomas Bjorn and Australia's Greg Chalmers.
Weir is among the group of golfers trying to climb into the top 54 on the Charles Schwab Cup points list in order to play at next week's Simmons Bank Championship. He began the week at No. 71, but he's currently projected to move to No. 53.