Niall Kearney carded a 68 to lead at the halfway stage at the BMW International Open in Munich.
The Dubliner followed up his opening 65 with five birdies and a bogey to climb to 11 under and move two clear of a five-way tie for second containing Adrien Saddier, Masahiro Kawamura, Bernd Wiesberger, Viktor Hovland and Jorge Campillo.
Kearney, 33, notched his first birdie on four before a run of three in succession on nine, 10 and 11. A bogey followed on the Par-3 17th. But he finished off his round in style with a birdie on 18.
Padraig Harrington was 10 shots further back but was just outside the projected cut mark on one under after a 71 which included eagles on four and six, and a pair of birdies, but also three bogeys as well as a double bogey on 16.
Jonathan Caldwell also missed the cut after a 75 saw the Northern Irishman slip back to one over, while Greystones' Paul Dunne who was also among the late starters finished on two over after another 73 at the tournament.
"I just feel really fresh," Kearney, who is ranked 599 in the world, told Sky Sports after his round.
"I have been home the last couple of weeks and I've had plenty of time to rest. I had been travelling prior to that quite a bit and it was great just to get home and recharge and then get back out.
"The course is fantastic and it suits my eye. It's old-fashioned with avenues and it's quite tight off the tee and I am really enjoying it."
Referencing his brilliant approach to the 18th from 260 yards that was fired straight at a pin just a few yards over the water, Kearney admitted with a smile: "Yes, it was a push. I was aiming at the left half of the green knowing that it was going to be a really difficult putt and I just got under it a little bit and it finished up great, but it wasn't my intended line."
Wiesberger played alongside Ryder Cup captain Harrington for the first two days as he looks to secure a place on the European side which will defend the trophy at Whistling Straits in September.
"He's very competitive and tries his hardest out there, even though he wasn't quite on it this week," Wiesberger said of the three-time major-winning Dubliner after a 68.
"But you can see, all of a sudden he makes a couple of eagles and you see it in his eyes. He was very focused on what he was doing.
"Hopefully the odd shot I hit over the last two days maybe stayed in the back of his mind - not so much the last three wood into the par five.
"At the end of the day we're still trying to compete out here, he has his stuff figured out off the golf course and results will hopefully determine who will be on his team."