The 40-year-old Bjorn shared second place with Britons Simon Khan, Rhys Davies and Gareth Maybin and Austrian Bernd Wiesberger. World number six Martin Kaymer and triple major champion Padraig Harrington were three shots off the lead.
Bjorn's season has gone from strength to strength, with victory at the Qatar Masters in February and back-to-back triumphs at the Johnnie Walker Championship and European Masters in August and September.
His title hat-trick came after a barren four-year spell was ended at the 2010 Estoril Open in Portugal.
Now the twice former Ryder Cup player, determined to feature in Jose Maria Olazabal's European side again next year, is eyeing his 14th tour title.
"It's gone well for me again in Portugal. I've loved the place since I came here with the national team as a young lad," Bjorn told reporters.
"I holed a few nice putts early on, then it was a bit scruffy coming in but all-in-all a good day's work.
"At the moment I'm finding it easy to score, even when I don't play well, but I've obviously had a lot of confidence for some time."
Kingston returned nine birdies and one bogey as the 45-year-old went in search of his third European Tour title.
"The conditions were hot but absolutely perfect and the course was there for the taking," said Kingston.
Harrington had the same thing in mind but said he attacked too much.
"If I wasn't thinking that 20-under is going to win this tournament I'd have played a lot better," the Irishman said after notching eight birdies and three bogeys. "I was pushing too hard and I was too gung-ho."
Harrington hit a stunning wedge approach to just two inches on the first, his 10th hole, to wipe out the memory of his shot into water at the 12th.
Last year's European number one, 2010 U.S. PGA champion Kaymer, is looking to improve on his fifth place in this season's money list.
The German holds the course record of 61 at the Victoria club on the Algarve.
"It's not a very difficult course and four years ago when I shot the 61 I only had 23 putts," Kaymer said.
"I only had to look at the hole and the ball went in. Today it wasn't quite the same but hopefully there's another 61 in me."
(Editing by Tony Jimenez)