The habit scoring well when you are not playing your best was something that Tiger Woods turned into an art form.

It now appears that Rory McIlroy is learning that dark art and in what must be a frightening move for his rivals, he’s threatening to start winning that way too.

On a day when Graeme McDowell continued his renaissance with a 69 for a share of 14th that might have been a few lower, McIlroy conjured up six seemingly effortless birdies — some of them stunning — to lurk two strokes behind Alex Noren on four under par.

The Swede, who finished second in this tournament at Emirates Golf Club last year, fired a six under par 66 to lead by one from countryman Peter Hanson, 2012 champion Rafa Cabrera-Bello of Spain, Trevor Fisher Jnr of South Africa and Australian Brett Rumford.

Defending champion McIlroy and the Desert Classic’s most prolific winner Els – who has won the event three times – are in an eight-strong group on four under, with McDowell and Stenson a further shot back.

McIlroy began his day with a bogey six on the par five tenth hole, but soon shook off that poor start with three birdies on the back nine, including a brilliant four at the par five 18th despite driving his ball into the water from the tee. The world number three added three birdies, a single bogey and five pars on the front nine to make a solid start to his title defence.

Having won his first event as a professional at the Desert Classic in 2009, McIlroy is seeking to join Els as a three-time champion.

McIlroy said: “It wasn’t the best way to start, bogeying a par five, and then even the bogey I made on the second hole, which is a birdie hole out here, was a bad mistake. But to bounce back and to birdie some of the tougher holes on the course, I was really pleased with that. 

"When I got myself out of position, I was able to get back in play and make my pars. So, considering the start, I’m happy with how the rest of the round went. I still feel there’s room for improvement in my putting, but it’s definitely got better. 

"Even since winning this tournament back in 2009, the strides I’ve made in my putting have been great. I feel like I’ve got a consistent routine in practice and that definitely helps on the course.”

Darren Clarke threatened to lead early in the day, playing seven holes in five under in the middle of his round to lead on six under before the wheels came off with five dropped shots in his last five for a one under 71.

After a bogey at the fifth, the European Ryder Cup skipper doubled the sixth and then bogeyed the difficult eighth and ninth to end the day tied 47th.

McDowell got off to a good start with an eagle three at the 13th, his fourth, and a birdie at the 14th. But he hit just five fairways and understandably stalled in the middle of the round, needing a birdie at the ninth to erase a bogey five at the sixth.

"I got to a fast start eagling 13 and birdieing 14,” McDowell said. “I gave myself some opportunities on the next six holes and didn’t take them. And I really didn’t drive it in the fairway enough. 

"I bogeyed six, probably the toughest par four on the course today, and it was nice to birdie the last.

“Scoring is not quite as low as it normally is here with the fairways being as firm and as fiery as they are. You have to control your ball here now, so it has changed a little over the years.”

The Portrush native has made no secret of the fact that getting married and having a child was a major change in his life and he took his eye off the ball, preferring to enjoy more time at home with the family than working hard on the range.

A late season win in Mexico was enough to drag him out of a slump that started in 2014 and dragged through most of 2015. It has given him something to cling to having put himself under too much pressure in the latter half of the year and fall from 15th to 86th in the world.

“There is no substitute for winning,” world No 69 McDowell said of his win in the OHL Classic at Mayakoba last November. 

“It wasn’t the best first half of the year but I felt like I worked hard and really dug myself out of a hole and played well the second half of the year. 

“I feel like I am carrying some nice confidence into this year and I feel like a weight has been lifted off my shoulders and I can go out there and relax and play some golf and hopefully have a strong year.”

Paul McGinley shot a two over 74 while Michael Hoey had a poor day, mixing four birdies with eight bogeys and a double in a six over 78.

The Belfast pro was far from his best, scrambling just once for par from eight attempts.

Round 1 scores

66 A Noren (Swe), 

67 T Fisher Jnr (RSA), R Cabrera-Bello (Esp), P Hanson (Swe), B Rumford (Aus), 

68 D Lipsky (USA), A Quiros (Esp), S Dyson (Eng), R McIlroy (Nir), G Storm (Eng), C Wood (Eng), B Wiesberger (Aut), E Els (RSA), 

69 O Fisher (Eng), G McDowell (Nir), J Morrison (Eng), H Stenson (Swe), N Holman (Aus), R Bland (Eng), B Evans (Eng), B Hebert (Fra), J Quesne (Fra), M Manassero (Ita), J Luiten (Ned), D Brooks (Eng), R Jacquelin (Fra), S Jamieson (Sco), J Allan (am) (Eng), 

70 S Kjeldsen (Den), R Fisher (Eng), G Stal (Fra), M Madsen (Den), D Willett (Eng), A Sullivan (Eng), T Jaidee (Tha), A Wu (Chn), S Gallacher (Sco), S Webster (Eng), D Horsey (Eng), E Pepperell (Eng), T Hatton (Eng), M Ilonen (Fin), R Paratore (Ita), B Dredge (Wal), K Aphibarnrat (Tha), B Dechambeau (am) (USA), 

71 A Cañizares (Esp), D Howell (Eng), F Zanotti (Par), D Clarke (Nir), T Lawrence (RSA), M Baldwin (Eng), J Carlsson (Swe), M Kaymer (Ger), G Havret (Fra), A Levy (Fra), T Fleetwood (Eng), B An (Kor), T Immelman (RSA), R Gouveia (Por), S Hend (Aus), W Ormsby (Aus), P Edberg (Swe), 

72 E Espana (Fra), P Larrazábal (Esp), L Weber (Fra), F Aguilar (Chi), N Elvira (Esp), G Bourdy (Fra), M Korhonen (Fin), R Rock (Eng), D Drysdale (Sco), H Porteous (RSA), C Lee (Sco), T Olesen (Den), R Kakko (Fin), J Campillo (Esp), M Kieffer (Ger), E Molinari (Ita), C Paisley (Eng), G Coetzee (RSA), J Hansen (Den), L Bjerregaard (Den), 

73 K Broberg (Swe), S Khan (Eng), M Warren (Sco), M Fitzpatrick (Eng), L Slattery (Eng), L Oosthuizen (RSA), R Dinwiddie (Eng), M Siem (Ger), P Lawrie (Sco), N Colsaerts (Bel), R Sterne (RSA), D Fichardt (RSA), D Foos (Ger), M Carlsson (Swe), N Fasth (Swe), A Johnston (Eng), 

74 B Stone (RSA), J Donaldson (Wal), M Ford (Eng), M Jiménez (Esp), R Karlberg (Swe), P Meesawat (Tha), M Lorenzo-Vera (Fra), P McGinley (Irl), R Ramsay (Sco), O Wilson (Eng), Z Scotland (Eng), 

75 J Lagergren (Swe), A Wall (Eng), R Karlsson (Swe), E De La Riva (Esp), L Corfield (Eng), P Doherty (Sco), L Westwood (Eng), 

76 T Pieters (Bel), H Otto (RSA), J Singh (Ind), S Gros (Fra), B Virto Astudillo (Esp), G Green (Mas), 

77 M Fraser (Aus), R Wattel (Fra), G Canizares (Esp), 

78 M Hoey (Nir), 

80 J Jeong (Kor), A Dodt (Aus), 

81 F Serghini (Mar), A Joudar (Mar), 

RET P Uihlein (USA).