Narrowed fairways, thicker rough and lightning fast greens made Emirates Golf Club a much tougher proposition than in recent years and a testing wind meant that anything under par was an excellent result in round one.
For a long time it looked like early starter David Lipsky would take the advantage into day two but Pieters recovered from a shaky start to his second nine with a hat-trick of birdies to get to five under.
Lipsky was his nearest challenger, a shot clear of South Africans Dean Burmester and Shaun Norris, Australian Lucas Herbert, Swede Robert Karlsson, Japan's Masahiro Kawamura, American Kurt Kitayama, Dane Søren Kjeldsen, Frenchmen Romain Langasque and Matthieu Pavon, Englishman Eddie Pepperell, Finn Kalle Samooja and China's Wu Ashun.
Defending champion Bryson DeChambeau was in the group at two under, with just 29 players under par.
Big hitting Belgian Pieters won his fourth European Tour title at last season's D+D Real Czech Masters and he was quickly the man to catch after starting on the tenth, making birdies on his opener, the 11th, 13th, 15th and 18th.
A double bogey on the first knocked him back and when he followed it with a dropped shot on the next, he had gone from one in front to two behind.
But the Ryder Cup star is made of stern stuff and he birdied the fifth and sixth before hitting a beautiful tee shot into the seventh for his third two of the round and a one shot lead.
"I've been working on my putting real hard and I just hope to see some progress," he said. "I saw that today, hopefully we can keep it up.
"I know I'm hitting the ball quite nice and I'm just looking forward to the next three days.
"It's always a bit scary starting out, you don't know what to expect even though you've put the work in - that competitive mindset sometimes takes a while to kick in. But I think today was one of my better rounds of the year."
Earlier, Lipsky took advantage of the par five tenth and holed a long putt at the 12th before further gains on the 17th and first moved him two ahead.
Norris made a fast start with birdies on the tenth, 12th and 13th but he was two behind as Lipsky picked up another shot on the second.
The American then made his only bogey of the day on the fourth and as he parred his way home, Norris reeled him in.
The 37-year-old birdied the 16th to join the lead and also made gains on the first and third to become the first man to six under, missing a golden chance from three feet for a three shot lead on the fifth.
He looked to be making serene progress but a triple bogey on the ninth after finding the water sent him tumbling backwards.
Karlsson and Kitayama were both bogey free in their efforts, while Pavon and Pepperell each had a single blemish on the card.
Burmester made seven birdies but had a double and two bogeys, Kawamura and Langasque both made six birdies but also dropped three shots, while Herbert, Kjeldsen and Wu all paired five birdies with two bogeys.
Samooja made five birdies and a double bogey on the ninth, a hole that gave up just four birdies all day.
American DeChambeau finished his round of 70 with the first of those, adding to three other birdies and two bogeys to sit two shots off the lead alongside German Sebastian Heisele, South African Erik van Rooyen and Frenchman Romain Wattel.