Though he had not competed in matchplay golf during that long span until he arrived at Dove Mountain this week, Piercy produced imperious form to eliminate the British world number three in the second round of an event Donald had won in 2011.
"I played really solid today," a beaming Piercy said after totally outshining former world number one Donald on a sunny afternoon in Arizona's high desert. "I hit every green in regulation.
"I got up early and tried to lean on him once I got up. It was just a solid day all around. I just tried to make some birdies and stay out ahead of him."
In 2007, Piercy hit the jackpot with a $2 million pay-day when he birdied five of the last six holes to triumph at the made-for-television, winner-take-all Ultimate Game tournament in his hometown of Las Vegas.
That success came on his fifth wedding anniversary and he has described it as his biggest thrill in golf.
"It worked out good for me there," Piercy said with a smile as he reflected back on his Ultimate Game triumph, before saying he had experienced less pressure at Dove Mountain this week.
"You know what, I actually feel really relaxed out there," he added. "Me and Luke's games are a lot different, and I feel like if I get things going, I've got a good chance of beating him.
"I played well, and he was off a little bit, that's why it looked so one-sided. I hadn't played match play for a long time, and I didn't know what to expect.
"But you're only playing one guy ... so just play solid golf and try to win," said the American, who won his second US Tour title at last year's Canadian Open.
Piercy spectacularly holed out with a four-iron from 221 yards to eagle the par-four fifth, then birdied the sixth, eighth and ninth to go 6up on Donald by the turn.
The 34-year-old American was effectively seven under par on his ball after being conceded a four-foot birdie putt at the short 12th to seal the upset win.
On one level, though, Piercy did not regard his victory as that much of a surprise.
"Tiger (Woods) raised the bar a lot, and everybody out here is better," he said. "It's not just 10 guys who are the best anymore. There are 50, 60 guys every week, and there are 60 guys here.
"When somebody is on, they're on. There's not as big of a spread between who the best players are and sort of the next tier."
Piercy likes the way his professional golfing career has steadily followed an upward curve.
"It's been building blocks, steps," he said. "I won in Reno first, which is sort of a smaller event, and then Canada is bigger. I've gotten into the WGC events and now the Majors, and I've got to feel comfortable playing in these.
"I feel like I can compete and I definitely want to win WGC events, Majors. One of my goals is to win a couple times in a year. Winning takes care of a lot. So if you win, then hopefully that elite will come."
- Sports & Recreation