England’s David Horsey covered the back nine in 28 as he made nine birdies in a course record-equalling 61 to take a one-shot lead at the opening round of the Saudi International powered by SoftBank Investment Advisers at Royal Greens Golf and Country Club.

On a day when the early starters took advantage of windless conditions and many of the afternoon wave — including Graeme McDowell, Cormac Sharvin and Paul Dunne — struggled in the breeze, Horsey made seven birdies on the homeward nine to lead by a shot from Scotland’s Stephen Gallacher with Austrian Ryder Cup hopeful Bernd Wiesberger third after a 64.

Six players shot five-under 65s with US Open champion Bryson DeChambeau the best of the 11-strong American contingent despite struggling to find fairways as world number one Dustin Johnson opened with a three-under-par 67 to match playing partners Tyrrell Hatton and Lee Westwood.

“I’m definitely very pleased,” DeChambeau said. “I was driving it a bit all over the place for the most part out there. Hit some good drives to six and seven. But was definitely struggling with the driver and a little bit of the irons, and I have to clean that up for tomorrow. If I can do that and put the way I did today, I'll certainly be pleased.”

Horsey, who was runner-up to Rory Mcilroy in the semi-finals of the 2006 West of Ireland Championship and has since gone on to win four times on the European Tour, admitted to being surprised by his score.

“It's a shock actually,” Horsey said. “I've been playing rubbish the last couple weeks. Didn't feel like I controlled my ball the first two events.

“I had a conversation with a pal back home last night, talking a few things through and suggested something that I work on away from the tournament.  Knowing me, I thought, well, can't get any worse, so I may as well try it and here we are.”

He added: “I didn't really feel like I missed many shots. I holed a couple of nice, lengthy putts as well and it all adds up to 61.”

Patrick Reed struggled in the toughest afternoon conditions, carding a one-under 69 as he failed to find his range on the greens.

“I didn’t really make any putts,” Reed said. “It was the same here last year. The putter seems to beat me up on this course.”

Lowry was among the morning starters but like Reed, he also failed to take advantage of some good ball-striking, making one birdie and one bogey in a level par 70 that left him tied for 72nd with defending champion McDowell and Ardglass star Cormac Sharvin.

McDowell turned in level par in blustery conditions but after picking but birdies at the 10th and 12th, he shanked his approach from a hanging lie in the left rough into a lake at the tough 13th and made a double-bogey six.

Another shot went at the 15th before he two-putted the last for a birdie four and a 70 as playing partners Paul Casey and Robert MacIntyre shot rounds of 69 and 71 respectively.

“Me and my playing partners, Bob and G-Mac, we genuinely struggled,” Casey said. “We found it very difficult. It's a great golf course. It's a hell of a test. But I'm just happy to get through under par.”

Sharvin birdied the first but then bogeyed the seventh and eighth to turn in one-over before playing the back nine in one-under for his 70.

The Co Down man struggled from the tee but while he bogeyed the 11th and 13th, he birdied the 10th, 15th and 17th.

Paul Dunne was two under par with six holes to go after birdies at the fourth and fifth but he ran up a quadruple-bogey eight at the treacherous 13th.

The Greystones man then bogeyed the 15th en route to a three-over 73 in his first start since last September’s Irish Open.

Saudi International powered by SoftBank Investment Advisers, Royal Greens G&CC (Par 70)

Detailed scores

61 D Horsey (Eng),

62 S Gallacher (Sco),

64 B Wiesberger (Aut),

65 R Fox (Nzl), T Pieters (Bel), C Hill (Sco), H Li (Chn), M Kinhult (Swe), B Dechambeau (USA),

66 M Kawamura (Jpn), A Sullivan (Eng), G Coetzee (RSA), L Canter (Eng), F Zanotti (Par), J Vegas (Ven), M Korhonen (Fin),

67 A Rozner (Fra), T Kanaya (Jpn), K Kitayama (USA), D Johnson (USA), L Westwood (Eng), J Luiten (Ned), T Hatton (Eng), V Perez (Fra), M Kaymer (Ger), T Detry (Bel), J Morrison (Eng), I Poulter (Eng), D Willett (Eng), J Winther (Den),

68 J Harding (RSA), A Otaegui (Esp), P Mickelson (USA), T Fleetwood (Eng), T Finau (USA), J Rose (Eng), A Wu (Chn), S Brown (Eng), J Walters (RSA), R McGowan (Eng), M Pavon (Fra), C Paisley (Eng), O Wilson (Eng), S Crocker (USA), V Hovland (Nor), C Bezuidenhout (RSA), G Migliozzi (Ita), M Schwab (Aut),

69 M Lorenzo-Vera (Fra), P Larrazábal (Esp), R Langasque (Fra), D Burmester (RSA), M Lee (Aus), K Na (USA), S Sharma (Ind), R Sterne (RSA), J Campillo (Esp), S Kjeldsen (Den), S Al Kurdi (Am) (Jor), K Samooja (Fin), A Arnaus (Esp), R Cabrera Bello (Esp), A Rai (Eng), J Janewattananond (Tha), J Suri (USA), P Reed (USA), G Forrest (Sco), R Fisher (Eng), P Casey (Eng), J Catlin (USA), J Stalter (Fra),

70 S Garcia (Esp), Shane Lowry (Irl), K Broberg (Swe), F Laporta (Ita), B Stone (RSA), J Hansen (Den), H Porteous (RSA), J Guerrier (Fra), H Hall (Eng), M Southgate (Eng), D Law (Sco), D Drysdale (Sco), R Hojgaard (Den), Graeme McDowell (Nir), A Johnston (Eng), A Chesters (Eng), D Lipsky (USA), J Kokrak (USA), L Herbert (Aus), Cormac Sharvin (Nir), G Higgo (RSA),

71 P Waring (Eng), W Ormsby (Aus), B Hebert (Fra), N Elvira (Esp), M Kieffer (Ger), D Howell (Eng), A Quiros (Esp), J Smith (Eng), G Green (Mas), W Nienaber (RSA), A Ancer (Mex), R MacIntyre (Sco), S Hend (Aus), A Levy (Fra), V Dubuisson (Fra), O Almulla (KSA), L Gagli (Ita),

72 E Rousaud (Am) (Esp), Z Lombard (RSA), H Stenson (Swe), M Jiménez (Esp), O Fisher (Eng), J Donaldson (Wal), R Paratore (Ita), A Bjork (Swe),

73 R McEvoy (Eng), K Aphibarnrat (Tha), E Molinari (Ita), C Wood (Eng), M Wallace (Eng), Paul Dunne (Irl), S Soderberg (Swe), S Valimaki (Fin), R Ramsay (Sco), T Pulkkanen (Fin),

74 M Warren (Sco), A Pavan (Ita), S Jamieson (Sco), E Els (RSA), T Bjorn (Den), J Schaper (RSA),

75 N Bertasio (Ita), J Scrivener (Aus),

76 R Jacquelin (Fra),

77 F Salhab (Am) (KSA),

80 S Al Sharif (Am) (KSA).