Second overnight after shooting a 68 to a 65 from Robin Dawson (Tramore), the Hallamshire player maintained his position by adding a one-under-par 70 to the Irishman’s 71.
There is a four-shot gap back to two players tied in third.
Fitzpatrick’s second round could barely have started any better as he eagled the 539-yard par-5 first.
Twelve consecutive pars followed before the Sheffielder took a couple of backward steps with bogeys at 14 and 15, but he birdied 16 to ensure a second consecutive round under par.
Malton & Norton’s David Hague had left himself only one behind Fitzpatrick after a 69 on Thursday, but he was 10 shots higher on day two with 79 and slid down to a tie for 37th.
He had six bogeys on his way out, including five in a row, and added another at 10.
His only birdie of the day came at 12, but he dropped further behind with bogeys at 14 and 16.
Fulford’s Charlie Thornton is Yorkshire’s second-highest player in 20th spot after scores of 70 76.
He had eight pars and a single blemish on his way to the turn, bogeying the fifth for the second day running.
The former England Golf Boys’ Order of Merit champion was unable to find a birdie on the day and suffered four more bogeys in his homeward run.
Wath’s Nick Poppleton and Bailey Gill (Lindrick) are in a tie for 30th after scores of 73 74 and 70 77 respectively.
On the front nine Poppleton sandwiched bogeys at four and five with birdies at two and seven, but then dropped shots at both eight and nine.
After starting home with five pars on the spin he bogeyed 15, got the shot back at 16, but shed one again at 18.
Gill was six over through 11 holes before seeming to get back on track by birdieing 12 and 13. But he derailed himself at the last, taking a double bogey on the 548-yard par-5 that he had birdied in round one.
Former Yorkshire champion Ben Hutchinson (Howley Hall) got off to a good start by reprising his first-hole birdie of day one.
However, three bogeys and a double at the 429-yard eighth had him out in 39.
He showed his mettle by playing the back nine in level par with seven pars, a birdie at 12 and a bogey at 15 and is tied with Hague after rounds of 73 75.