Several teams made significant moves at Kingston Heath, but none bigger than the Danish duo, who produced a sensational 12-under par 60 to rocket to the top of the leaderboard at 12-under overall -- three clear of China and four ahead of Spain.
Olesen admitted he thought about the possibility of scoring an elusive 59 as the pair drilled eight birdies and two eagles to stun the galleries, a blitz that included a 139-metre hole out from Kjeldsen on the par four third.
The younger Olesen was the star, contributing six birdies and an eagle, but the accurate ball striking of world No.45 Kjeldsen playing first allowed his partner, ranked 67, the freedom to explore the possibilities in cold and windy conditions.
Kjeldsen said the pair complemented each other.
"Thorbjørn's very flashy, he hits very far off the tee and overall he's just got an amazing game," the 41-year-old said of his 26-year-old countryman. "Whereas myself, I'm sort of like a train -- I just arrive on time but without too much of the flashy stuff."
Kjeldsen added that he could play around Kingston Heath for the "rest of his life", portraying the infinity he has quickly developed with the course.
"This is my kind of golf," the four-time European Tour winner said. "You don't just get up and whack it as hard as you can. You have to think your way around."
As the format switches back to the more difficult "foursomes" (where players hit the same ball taking alternate shots) on Saturday, Denmark will be joined in the last group out by the event's other surprise package -- China duo Li Haotong and Wu Ashun.
The Chinese have become fan favourites this week courtesy of their energetic "chest-bumping" celebrations, and there was plenty to be excited about as they followed up their impressive 70 on Thursday with a seven-under 65.
Overnight leaders Spain kept their title pursuit on track with Rafa Cabrera Bello and Jon Rahm producing a five-under round of 67, while American pre-tournament favourites Rickie Fowler and Jimmy Walker ensured they would be a factor over the weekend by carding their own 67.
England and Italy were the other big movers on day two, each posting rounds of 66 to move to seven-under and equal with the US and France, who conjured a five-under round of 65.
New Zealand (64), Netherlands (64) Japan (65), Taiwan (65) Scotland (65), Sweden (66), India (66), Thailand (66), Wales (66) and South Africa (66) all had rounds of six-under or better to either catapult up the leaderboard, or make amends for a poor showing in the foursomes.