McDowell arrived in Doha ranked 91st in the world and admitting he faced “a long road” back to the sort of golf which produced 10 European Tour titles and four consecutive Ryder Cup appearances.
However, the former US Open champion looked close to his best as he took advantage of unusually calm conditions to card a six-under-par 66 and lie two shots off the pace set by Welshman Bradley Dredge.
Starting from the 10th, McDowell birdied his first three holes and picked up further shots on the 14th, 16th and 18th to race to the turn in just 30 shots, before adding another birdie on the second.
The only blemish on the 37-year-old’s scorecard came with a three-putt bogey on the sixth, but the Northern Irishman was understandably pleased with his first competitive round of the year.
“My expectations were fairly low, I suppose, coming in,” said McDowell, who had failed to card a single birdie in the pre-tournament pro-am. “My game felt a little bit rusty the last week or so and I was expecting tougher conditions.
“Now that I’ve got off to a good start, I’ve got to keep my expectations in check and not get too far ahead of myself, just keep calm and keep enjoying myself and stay patient and see what happens.
“First round and tournament of the year and to birdie 10, 11, 12 was a special way to start and certainly got me in a very relaxed frame of mind.
“It was nice to keep building and keep hitting good shots but there is a long way to go. There are lots of good players here and I’ll definitely keep the head down and hope to keep playing well.
“I felt good on the greens, my iron play was very good and I got the ball in play mostly off the tee. It’s only round one but I liked the way I felt out there.”
Dredge was fourth in Qatar last year and demonstrated his liking for the course with eight birdies in a flawless 64 to finish a shot ahead of Finland’s Mikko Korhonen.
“Without the wind it makes it a lot easier to get the score going and get the putts in and get in with some sort of number,” said Dredge, who has not won a European Tour event since 2006.
“I prefer it a little bit more windy and I get used to it around here as well. It’s quite a good challenge. The greens are always firm, so it’s always tough to get the ball close to the hole.”
On a day when 84 players in the 126-man field broke par, McDowell was joined on six under by Thailand’s Kiradech Aphibarnrat and 23-year-old Englishman Nathan Kimsey, who secured his card by winning the qualifying school in November.
Ireland’s Paul Dunne and England’s Simon Dyson were part of an eight-strong group on five under, with Ryder Cup captain Thomas Bjorn, Ernie Els, Alex Noren, Richie Ramsay and South African Open winner Graeme Storm among those a shot further back.