Sato shot a 67 and Jaquelin a 65 to lead the European Tour event by one shot over England's Jonathan Lomas. Seven players were another shot back.
Jacquelin has not won on the tour but is in eighth place in this year's Ryder Cup standings.
"In my first five years I finished between 120th and 150th in putting. That's the big difference now," Jacquelin said. "The way to win is not to be impatient, but if it happens here I won't be surprised."
Sato is trying to become the first Japanese winner on the European Tour in 20 years. Isao Aoki won the European Open in 1984.
Lomas, who has won once in 300 tour events, finished with four birdies in the last five holes for a 64 to put him 10 under.