Tom Vaillant, of France, a two-time winner on the smaller Alps Tour but still looking for his first European tour title, shot 67 on Saturday (Sunday AEST) and was in second place, putting him in the last group with Fitzpatrick for the final round before a home crowd at Le Golf National in Paris.
Fitzpatrick was dialled in from the start, holing a seven-foot birdie putt on the opening hole, reaching the green in two on the par-five third for birdie and then hitting wedge to four feet for birdie on the sixth.
He dropped only one shot, and he got up-and-down from just off the green at the 18th to complete three rounds at 19-under 194.
"I feel like I'm in a position that if I go and shoot a good round tomorrow, then obviously it makes it almost impossible to catch me," Fitzpatrick said. "But long way to go, and just take it hole by hole."
Fitzpatrick has already won the Valspar Championship and the RBC Heritage on the PGA Tour, along with teaming up with younger brother Alex to win the Zurich Classic of New Orleans.
But he was disappointed with his missed cut in the British Open, along with sub-standard outings in the PGA Tour's post-season.
Eugenio Chacarra of Spain, at No.3 in the Race to Dubai, shot 62 and was among five players who were tied for third, but defending champion Michael Kim hit into the water on the final hole for a double-bogey that gave him a 70 to fall seven shots behind.
Vaillant has only three top 10s in his three years on the European tour, though he was thrilled with his support from the home crowd.
"It's amazing. Whatever happens tomorrow, it's something I will never forget — the final group here in the French Open," Vaillant said.
Jason Scrivener continued his encouraging week as the leading Australian by firing a third-round 68 that's left him at 10-under, tied for 14th place. Compatriot Anthony Quayle was joint-55th, on three-under, after a 72.
