Mijajlo Marsenic with ten goals and world handball player Mathias Gidsel with six goals were the key profiles behind the away win, while THW keeper Andreas Wolff, who was outstanding in the cup win in Cologne last weekend, did not come close to his usual level of performance with only four saves.
Füchse are aiming for the first championship title in the club's history, with eight games still remaining. Compared to the other teams, the Foxes also have the significantly better goal difference.
Siewert satisfied: "Extremely important points"
The visitors pulled three goals ahead for the first time midway through the first half (12-9 in the 20th minute) and maintained a narrow lead throughout the match.
The lead was five goals at times, but THW fought its way back three days after its 13th cup triumph - and reduced the deficit to one goal with six minutes left. However, Füchse held their nerve and celebrated their 19th win of the season.
To the match centre: Kiel vs. Foxes
"It's always something special to win here. First and foremost, these are extremely important points," said Berlin's coach Jaron Siewert to Dyn: "We're super happy."
Füchse moved two points clear at the top of the table for the time being - but MT Melsungen can draw level again with a home win against VfL Gummersbach on Saturday.
Meanwhile, the cup winners from Kiel are out of the title race and are now six points behind the Foxes.