Jacobson, who finished third in Malaysia last week, leads by one ahead of 2010 British Open winner Louis Oosthuizen who signed for the day's lowest score of 63 to take a share of second place alongside Australia's Adam Scott on 134 total.
Starting the day in tied-second, Jacobson carded his first birdie on the seventh hole before adding another on the par-four ninth to reach the turn in 34.
He started his outward-nine with another birdie on the 10th hole before a hat-trick of birdies starting from the 14th hole ensured that he would head into the weekend with the lead.
"I think I've just been striking the ball really well. I've been driving the ball really well over these first two days," said Jacobson.
"I got a new driver a couple of weeks ago and it just seems to work really well. I feel I've been having pretty good distance off the tees, and if I can hit it straight, which I have so far, I'm going to get some good looks with my irons," added the Swede.
Meanwhile Oosthuizen surprised even himself after a sparkling 63 skyrocketed him up the leaderboard.
"I don't think I've ever shot a 63. I think I've shot 62 once in a tournament round, but you know, it was probably at my local course back in South Africa that I last shot a 63," said the South African who completed his first round in tied-30th place after an opening 71.
"I don't think I missed a green today as I hit the ball really well. It was nice, a good, solid day for me," added Oosthuizen.
Scott, winner of the last WGC event in Akron in August, also made his quick move up the top with a brilliant outward 31 that was highlighted by six birdies and one bogey.
The Australian then charged home with three birdies against another bogey on the 15th hole to stay in close touch with Jacobson.
"It was a good round today to keep pace with the leaders. I got off to a fairly fast start on the front-nine. It was nice to make a couple on the back nine to take advantage of the good front-nine," said Scott.
"I'm pleased to be in touch but obviously scoring is low, so I'm going to have to play well on the weekend to keep in touch with them," added the Australian.
Meanwhile, Thongchai Jaidee of Thailand continued to put Asia in the spotlight with a second round three-under-par 69 at the WGC-HSBC Champions on Friday.
Thongchai posted a two-day total of seven-under-par 137 to stay four shots back of Jacobson.
Thongchai, who started the day in tied-fifth, turned in 34 after birdies on holes four and seven. He moved to within three shots of the lead after posting another birdie on the par-three 12th.
The Thai's only blemish came at the par-four 15th but he recovered well with a closing birdie on the 18th hole to head into the weekend rounds beaming with confidence.
"I played very well today, same as yesterday. I made only one bogey today which was okay. Overall it was a solid round," said Thongchai.
The Thai ace, who had to endure a sore neck all-day during his first round, has recovered and is confident of making a charge.
"My neck is getting better. I slept in a very bad position the night before. But now, it better. I couldn't even turn much yesterday but I'm feeling good now and ready for the weekend," said Thongchai.
Asian Tour honorary member K.J. Choi of Korea also ensured that another Asian player would feature prominently on the leaderboard after returning with a 70.
The Korean, who has eight wins on the PGA Tour including the Players Championship earlier this year, is confident of stamping his mark against the elite field once he overcomes his fatigue.
"I'm just feeling very tired from the week's activities and functions. I plan to have an early night tonight and hopefully I'll be back all recharged for the weekend," said Choi.
Choi enjoyed a flawless front-nine with birdies on holes two, four and seven to reach the turn in 33.
However, he could not complete that bogey-free run in his homeward run after he traded two bogeys against a lone birdie on the 17th hole.
"I was not swinging as well as I wanted it to be. But it's okay, I'm still in contention and after a good sleep tonight, I'll be back," said Choi.