But Armitage is only one behind, alongside fellow Yorkshireman Chris Halley (Malton & Norton), as he looks to win his second consecutive HotelPlanner.com EuroPro Tour event.
Brian Casey carded a second-round 64, seven under par, to lead at Moor Allerton on five under par with 36 holes to play in Leeds.
The Irishman finished second in the Tree of Life Championship behind Armitage at Close House last week.
Greg Payne (Chobham) and James Ablett (Lee-on-the-Solent) are also just one behind Casey, who went two better than the tournament’s next best round so far with his second-round 64.
“My goal was to go out and pick my shots and make sure I controlled it in the wind, because [on Wednesday] I let a few shots slip and that cost me,” said Casey.
“I have been in good form and have some good things to look forward to; I am playing Russia next week for my first start on the European Tour. I have been building towards that and the second place last week has really helped.
“Playing 72 holes suits me. I think it suits everybody because it gives you an extra chance to hit some form during the week.”
Casey had begun the day on the provisional cut mark but quickly moved away from that with a birdie at the 11th and an eagle at 12, having started on the 10th tee.
Two more birdies came at 16 and 17 to see him go out in 31 and he broke par three times on his closing nine, with a bogey at the seventh his only blemish.
Overnight leader Armitage, who opened with a 66, carded a second round 72, one over par.
He had birdies at the fifth and 12th holes, having started at the 10th, but dropped shots at the fourth, seventh and eighth.
Halley also got his round underway at the 10th and after dropping a shot at the 11th birdied the next two holes.
He also birdied 17 and 18 for a first nine of 33. He covered the front nine, his second, in 34 with three birdies and a couple of bogeys, adding a 67 to his opening 71.
The championship, the first 72-hole event in the third-tier tour’s history, continues on Friday and concludes on Saturday.
The leading 50 players and ties progressed to the third round with all of those competitors two over par or better proceeding to play a further 36.
The final round takes place on Saturday and will be filmed for a two-hour highlights package to air on Sky Sports on Tuesday, September 8. Spectator entry is free throughout the event.