After an overnight downpour delayed the start of play by three hours, it was raining birdies for the 43-year-old Dane as he left a world-class field trailing in his wake with a dynamic five-under-par 67 at the tour's flagship event.
Bjorn, who has been at the top of the leaderboard since firing a record 62 in the opening round, picked up strokes at the 11th, 12th, 13th, 14th, 15th and 16th before adding another at 18 to rack up a 15-under total of 201 at Wentworth.
The performance was all the more laudable after he began his round with an ugly double-bogey six at the first caused by a hooked drive.
Luke Donald (68), the 2011 and 2012 champion, was in second place on 206, one ahead of Irishman Shane Lowry (73).
Former world number one Rory McIlroy (69), looking more assured with every passing day following his midweek break up with fiancee Caroline Wozniacki, was tied for fourth spot on 208 with Dutchman Joost Luiten (67).
"The putts just started dropping and all of a sudden you get in that zone or that frame of mind where everything goes your way," Bjorn told reporters of his championship record sequence of six birdies in succession.
"It was one of those days where things roll your way. It was a remarkable run of holes on the back nine."
Bjorn has chalked up 19 birdies in 54 holes this week but he is certainly not taking the $942,414 first prize for granted.
"There are a couple of names on that leaderboard you should never count out of your mind," he said. "I've got to go out and play some good golf and try and be aggressive when I can and try and be smart when I don't need to be aggressive.
"If I get a bad start tomorrow it's very much an open tournament so I've got to stay focused and determined. It's a dangerous lead, that's for sure."
Bjorn, three times a runner-up in majors without managing a breakthrough victory, will not be getting too pent up about the fact he is gunning for the biggest victory of his career in Sunday's final round.
"I view it as any other golf tournament," he said. "You want to be in these positions, work hard and get yourself in with a chance of winning and it doesn't really matter where it is.
"This is obviously a big event to the outside world but as a player you try and play it down."
Former world number one Donald said he played "stress-free" golf on Saturday.
"It probably wasn't that interesting to watch at home but when you play this course without making any mistakes, that's fun," said the Chicago-based Englishman.
"I had some chances around the middle of my round, just didn't quite get the putts in and didn't hit my irons really close enough. To birdie the last two holes though was a big momentum for me."
McIlroy, who missed the cut in three of his previous six starts in the tournament and has never won the event, said he was warming to Wentworth.
"The way the golf course is at the minute, with it being soft, I think I can play it a little bit better," said the Northern Irishman.
"I've had big leads and let them slip and come from behind and won. Eighteen holes of golf is still a long way to go but I'm going to need something very special, maybe something similar to what Thomas did the first day."
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