Donald set a tournament record by taking only 20 putts, which allowed him to tie a tournament record by opening with 8-under 64 and a three-shot lead over a group that included Jim Furyk and Jason Day, who bogeyed his last two holes.
What seemed like a normal round at Muirfield Village turned extraordinary for Donald when he rapped in a 12-foot birdie putt from the fringe on the par-3 eighth hole, starting a streak of six consecutive birdies. He one-putted nine holes in a row until a routine par on the 18th hole to match the lowest opening round at the Memorial.
"That doesn't happen very often," Donald said.
Even rarer is the sight of Woods spending so much time in the middle of the fairway.
Woods went with a slightly higher loft in his driver (10 degrees) and continued to make strides with his swing. He didn't miss a fairway until his 3-wood on the 18th hole deflected off a tree and landed in a bunker.
Scoring starts with the putter, however. Woods missed an 8-foot par putt on the final hole, and his other bogey came on a three-putt at the 13th. He had to settle for 69, and few complaints.
"Everything felt pretty good to some degree," Woods said. "My swing felt good. Even my putting stroke felt good. A couple of bad pitches here and there, but overall, I felt like I controlled the ball well all day. With the wind blowing like this, you have to hit it flush. I did that all day. I didn't miss any shots."
Furyk, who won the Memorial seven years ago, birdied three of his final four holes for 67. He was joined by Ted Purdy, Thomas Aiken and Day, the 21-year-old Australian who missed a playoff by one shot last week at Colonial. Day was 7-under with three holes to play, but made bogey from the bunkers on his final two holes.
Augusta native Charles Howell shot 75. He had two bogeys and a double bogey in his first five holes to go with just two birdies.
All of them were chasing Donald throughout a day that began cool and breezy and became warm and blustery.
Donald, who had only two sub-70 rounds at Muirfield Village, hit the opening tee shot and made bogey.
He was headed for another bogey on the second hole until he chipped in from 80 feet short of the green. He made eight birdies over the last 11 holes. And his score was an eyesore for those teeing off in the afternoon.
"That's rough when you walk to the first tee and you're already eight behind," defending champion Kenny Perry, who finished the day eight shots behind after two late bogeys have him 72.
Stewart Cink was among those at 68, while those at 69 with Woods included Mike Weir and British Amateur champion Reinier Saxton.
Woods painted an optimistic view of his immediate future.
"The swing is starting to come around," he said. "I'm starting to feel good now. It's been a long time. I'm starting to get my power back. Everything is starting to come around now."