SECOND ROUND LEADERBOARD:
-8 T Jaidee (Tha) -7 MA Jimenez (Sp), S Dodd (Wal), L Westwood (Eng) -6 E Molinari (It), C Schwartzel (SA), M Fraser (Aus), A Quiros (Sp), R McIlroy (NI)
Selected others: -4 P Casey (Eng) -3 D Clarke (NI) -2 R Fisher (Eng), R Bain (Sco) -1 T Watson (US) +3 C Montgomerie (Sco)
Westwood won in Dubai in last year's World Championship
European number one Lee Westwood carded his best round at the Emirates Club to move one off the lead at the halfway stage of the Dubai Desert Classic.
Westwood's bogey free 65 was his lowest in 50 rounds at the course and took him to seven under with Welshman Stephen Dodd and Spain's Miguel Angel Jimenez.
Defending champion Rory McIlroy found water at the last for a double bogey and his 70 leaves him one further back.
Asian number one Thongchai Jaidee leads after a 66 containing no dropped shots.
Westwood birdied six of the opening 14 holes and had a share of the lead after a neat up-and-down from the rough at the 359-yard par-four 17th, where he drove the green.
He resisted the temptation to go for the green in two at the 564-yard closing hole, perhaps influenced by playing partner Henrik Stenson suffering a watery fate, but missed a 10-foot putt and could only par the hole.
I am still happy where I am heading into the weekend
"I think we have had the hardest conditions over the first couple of days in the morning and then the afternoon but you try and make the best of whatever is thrown at you," said the 36-year-old, who opened with a 72 on Thursday.
"If you come out on the right end of that obviously it gives you a massive confidence boost and it's a big pat on the back.
"It's the goal all the time to get into contention and keep testing yourself and getting accustomed to being under pressure."
McIlroy, meanwhile, was three shots clear following a run of four consecutive birdies around the turn before his unfortunate finish.
"There is a little bit of a sour taste in the mouth after the last hole," the 20-year-old admitted. "I had not made a mistake all day and to do it at the last was disappointing, but if I make two birdies in the first two holes tomorrow all is forgotten.
"I am still happy where I am heading into the weekend."
Thongchai who secured two European Tour victories last season, and was 13th in the Open at Turnberry, is profiting from lengthy sessions on the practice putting green to hone his stroke.
"I played very consistently, it was a solid day," said the 40-year-old, a former paratrooper in the Thai army, who topped the Asian order of merit for a third time in 2009 and hopes to move up from 59th to reach the world top 50 in time to qualify for the US Masters in April.
"I hit 13 greens in regulation and missed just five fairways. I am very confident because my putting is getting better, that's why my game is getting better."
The cut came at plus two which was one too many for Ryder Cup captain Colin Montgomerie, who was unable to record a birdie in his 76.
Ross Bain is the leading Scot, after shooting a second round of 71 to sit 1 under par.