It was his third straight sub-70 round and will be looking to hold off a group of challengers which include fan-favorite and Germany's very own, Bernhard Langer.
Langer, who battled through a case of food poisoning on Friday, showed no residual effects of the problem as he posting a 5-under 67 that took him to 16-under for the tournament.
Im not 100% but much better than yesterday, said Langer, referring to his bout with food poisoning in the second round. I hope to be in really good shape tomorrow.'
Tied for second with Langer is England's Richard Bland, who lost the second-round lead despite carding a 3-under 69.
Ian Poulter and Jamie Spence, who shared the lead with Bland after Friday's round, both shot 70s and fell to three off the pace.
John Bickerton and David Lynn are four back of Bjorn at 14-under-par.
Bjorn, in third place going into Sunday last year before stumbling home with a 76, is hoping for a solid performance on Sunday that will enable him to get his first victory of the year.
Bjorn has won at least one event in each of the previous four seasons, his last coming at the 2001 Dubai Deset Classic, where he outdueled world's number one Tiger Woods.
With only three top-10 finishes on the year, Bjorn has fallen to 38th in the world golf rankings though a solid 15th place at last week's WGC-NEC had him feeling good going into this week.
Its been a while and it is nice to be in the mix and feel comfortable about it. Its been a long time coming and I feel my game is coming together,' noted Bjorn. 'I feel all the hard work I have done is just starting to benefit me on the golf course. I am getting back to thinking right on the golf course. Its progressing nicely.'
Up until the 14th hole Bjorn had run a streak of 41 holes without a bogey, yet saw him card an amazing 18 birdies in that same span. He quickly added another birdie on the 16th to offset the lone bogey and, with his two-shot advantage, has him looking to avenge last years' final-round collapse.
American John Daly, who admitted to being jet-lagged and wanting to, 'just sleep,' nevertheless cranked out eight birdies and moved to 11-under-par. The defending champion said that that was probably a bit to far off the lead to have a realistic chance at back-to-back titles.
Full-field scores from the BMW International Open