The 30-year-old, who topped the standings heading into the season-ending $8 million Rolex Series event, started the day three shots off the lead, held by Scottish-based Frenchman Victor Perez, after a bogey-free two-under-par 70.
But, after Englishman Laurie Canter started with six birdies in the first seven holes on the Earth Course at Jumeirah Golf Estates to briefly hit the front, Reed quickly moved up a gear in the final lap of the 2020 European Tour campaign.
The 2018 Masters champion, who has a good record in this event, including a second-place finish in 2018, birdied the second, third, fifth, seventh and eighth to be out in 31.
After starting for home with another birdie, he then dropped his first shot of the week after missing the green with his approach at the 12th before quickly finding his stride again with back-to-back birdies at the 15th and 16th.
Capping a brilliant day’s work, Reed closed with a birdie at the par-5 18th for an eight-under 64 to sit 10-under at the halfway stage, two ahead of Englishman Matt Fitzpatrick in the battle for a top prize worth $3 million and a pile of Race to Dubai points.
”Anytime you shoot eight-under par, you're always happy,” said Reed, who has embraced being a European Tour member since joining the circuit in addition to the PGA Tour. “I feel like today I got off to a little better start than I did yesterday and the putter was working a little bit.
“Yesterday I felt like I did a lot of things pretty well, just putts weren't really falling and a couple iron shots weren't as close as they needed to be.
“Today I tightened it up. I was able to hit the ball a little closer, give myself more opportunities and was seeing the lines a little better today.”
Fitzpatrick, who won this event in 2016, holed a monster birdie putt at the 17th to be a danger heading into the weekend, with two other Englishmen, Canter and BMW PGA champion Tyrrell Hatton, both on seven-under.
Tommy Fleetwood, who sits second in the Race to Dubai standings, and two-time Order of Merit winner Lee Westwood are in a group on six-under, but, on this sort of form, Reed will be a tough man to beat.
“I'm happy in the position I'm in,” said the world No 11. “I know that if I take care of business and win the golf tournament, then the Race to Dubai will take care of itself.”
Reed won the WGC-Mexico Championship earlier in the year and recorded top-15 finishes in the three majors played this season, admitting he has benefitted from a new swing he’s been working on with coach Sean Hogan.
“I think the biggest thing is the consistency,” he said of the difference that has made. “In the past, when I was swinging well and hitting the ball well, I could hit it close all day.
“But it was the days I was a hair off that the ball was just getting away from me too much, whether it was off the tee, iron shots into the greens. I was having to lean too much on my short game.
“Ever since I started kind of with the new swing, it just feels a little bit more controllable. The misses are playable as far as you can still handle them, get up-and-down or even have a putt for birdie.”
Fitzpatrick, who is bidding to land a six European Tour win, is hoping his winning experience four years ago will stand him in good stead, but, in Reed, he feels up against one of the best players in the world around the green.
“Patrick has got a brilliant short game,” said the Yorkshireman. “Don't get me wrong, his whole-round game is brilliant, but I've always admired him for his chipping and pitching and I think he's very underrated on that front.
“When he is going to be out of position tomorrow, which is inevitable as everyone is, in my mind I back him to get up-and-down nine times out of ten.
“So it's definitely going to be a grind. But I'm really looking forward to the challenge, and to be in that last group is always exciting.”
Canter, who is seeking a maiden win on the top tour after finishing second in both the Italian Open and Portugal Masters this season, carded a six-under 66 after his blistering start to sit two three behind Reed.
“It was weird as my range session was not great,” said the 31-year-old. “I then hit it right off the first tee but got away with it, hit a great shot from there and, for whatever reason, started to swing it better.
“It was one of those golf moments where it can go either and I got off on the right side of it and it went well from there.”
After a shaky back nine left him having to settle for a 74, Perez dropped seven shots off the pace on three-under, with Bob MacIntyre one better after a level-par 72 left him in a share of 12th spot.
“I actually played better than yesterday,” said MacIntyre, who needs to finish seventh or better to break into the world’s top 50 for the first time. “I drove the ball really good today. I was never really out of position.
“Didn't hit my iron shots as close as I would have liked, hence there wasn't many birdies. But I'm delighted with the way I fought there at the end (saving par after an adventurous journey up the 18th).”
Scott Jamieson (70) and Marc Warren (72) are both on level-par, two better than Connor Syme (73) and five ahead of Grant Forrest (74).