Graeme McDowell continued his love affair with Sheshan International Golf Club when he carded his 10th successive round in the 60s there to lead the WGC HSBC Champions by two shots in Shanghai.
On a day when Shane Lowry struggled to a six over 78, world No 17 McDowell raced to seven under after 12 holes thanks to a superb driving and putting display only to drop two shots in his last six holes.
A five under 67 was still pleasing for the Potrush man, who birdied the 10th, 13th, 14th, 16th, 17th, second and third before bogeys at the fourth and eighth took some of the gloss off an otherwise impressive performance.
"I got off to a flier today but it was tough you know, the wind changed around from what we played the course in practice," said McDowell, who leads from Martin Kaymer, Tommy Fleetwood, Rickie Fowler, Chris Kirk, Brandt Snedeker and Tim Clark.
An impressive 44 under par for his last 10 rounds at the venue, McDowell added: "I only missed one fairway all day which is key on this course, especially with the rough up like it is this year.
"The greens are very fast so you have to get on the right side of the flag and I managed to do that. You'll take five under every day of the week! I like the course, love it even, hopefully I can maintain this position going into the weekend."
His first costly mistake of the day did not arrive until the par-three fourth, where he found sand off the tee and could only splash out to 20 feet from a difficult downhill lie.
After great par saves at the sixth and seventh, he missed his only fairway of the day at the par-five eighth and bogeyed after leaving himself a lengthy third shot to the 603-yard monster after being forced to lay up.
“A big key to this golf course is driving the ball well and I drove it very well today," said McDowell, who is skipping next week's Turkish Airlines Open and needs a good week to climb into the top 15 in the Race to Dubai who will split the Bpnus Pool after the season-ending DP World Tour Championship.
"I think I missed only one fairway, which is very important; it set up a few opportunities. I had a beautiful start, but all in all I’m very pleased with five under on a reasonably tricky day.
"This is as tough off the tee as I think I've ever seen this golf course. It’s very tricky if you miss fairways – the rough is penal. I think they’ve got it just right this week. It's a really nice balance out there of risk/reward par fives and a drivable par four, some tough holes and some water - there's just the right amount of everything.”
McDowell is working hard on his short game ahead of the 2015 season and while he's sporting a bandage on his left wrist as a result, he dismissed any concerns.
"My left wrist doesn't seem to like it," said McDowell. "But nothing too sinister."
Third behind Dustin Johnson at Sheshan International 12 months ago, McDowell's form in the WGCs has been excellent with six Toop-10s from his last seven appearnaces stretching back to the beginning of the 2013 season.
Lowry is 51st in the world and on the cusp of making a breakthrough that could see him play in the Masters for the first time next April.
A six over 78 was not what he had in mind on a track where he started brilliantly two years ago (66-68) only to fade to 32nd after a 72-75 weekend.
He bogeyed the first, birdied the fourth but then then dropped five shots in the next five holes to turn in 41 before adding two bogeys and just one birdie on the back nine to end the day tied for 71st in the 78-man field.
He wasn't the only player to suffer.
Ryder Cup star Victor Dubuisson shot 76 and FedEx Cup champion Billy Horschel an 80.
Round 1 scores
67 G McDowell (Nir)
69 B Snedeker (USA), T Fleetwood (Eng), M Kaymer (Ger), T Clark (RSA), C Kirk (USA), R Fowler (USA),
70 D Van Der Walt (RSA), L Oosthuizen (RSA), K Hyung-Sung (Kor), J Holmes (USA), J Van Zyl (RSA), L Westwood (Eng), I Poulter (Eng), A Scott (Aus), H Stenson (Swe), B Haas (USA), J Spieth (USA),
71 T Jaidee (Tha), J Donaldson (Wal), K Na (USA), R Henley (USA), B Todd (USA), O Wilson (Eng), P Reed (USA), B Watson (USA), J Blixt (Swe),
72 M Siem (Ger), T Olesen (Den), M Leishman (Aus), K Bradley (USA), S Gallacher (Sco), J Rose (Eng), T Bjørn (Den), G Coetzee (RSA), J Dufner (USA),
73 J Senden (Aus), Z Lianwei (Chn), H Iwata (Jpn), J Walker (USA), G Woodland (USA),
74 H Matsuyama (Jpn), S Stallings (USA), W Ashun (Chn), S Garcia (Esp), H Otto (RSA), C Schwartzel (RSA), L Donald (Eng), A Levy (Fra), H Mahan (USA), D Fichardt (RSA), R Palmer (USA), E Els (RSA), A Lahiri (Ind), R Moore (USA),
75 M Jones (Aus), P Larrazábal (Esp), M Ilonen (Fin), L Hao-Tong (Chn), L Wen-Chong (Chn), M Warren (Sco), M Every (USA),
76 F Aguilar (Chi), A Lascuna (Phi), D Ze-Cheng (Chn), M Hendry (Nzl), V Dubuisson (Fra),
77 Y Takeya (Jpn), K Streelman (USA), J Luiten (Ned),
78 J Knutzon (USA), M Jiménez (Esp), S Lowry (Irl), D Lipsky (USA), H Mu (Chn),
80 B Horschel (USA),
85 J Jeong (Kor),
86 B Ninyette (Aus),
RTD K Stadler (USA), G Delaet (Can)