Sweden's Oscar Floren carried on where he left off on Thursday as the Irish Open resumed in windy conditions at Carton House.
Floren carded a flawless six-under-par 66 late in the first round to claim a one-shot overnight lead ahead of former champion Shane Lowry, Michael Hoey, Joost Luiten, Peter Uihlein and France's Jean-Baptiste Gonnet.
And the 29-year-old, who has a best finish of 25th on the European Tour this season, was quickly back among the birdies in the second round, picking up shots on the first and fourth to improve to eight under par.
That increased his lead to two shots over Madeira Islands Open winner Uihlein, who had started on the other side of the course and birdied the 10th, with former Ryder Cup captain Jose Maria Olazabal a shot further back after two birdies and one bogey in his opening five holes.
Hoey, whose opening 67 had come exactly a week after his wife Bev had given birth to their first child, had bogeyed the 11th to drop back to four under.
Graeme McDowell, who said earlier this week that winning the Irish Open was on his golfing "bucket list", was seven shots off the pace after an opening 71 and one birdie and one bogey in his opening four holes on Friday morning.
And former world number one Rory McIlroy was even further down the leaderboard, the two-time major winner admitting to feeling "a little lost" after a first round of 74 that left him struggling to make the cut on Friday afternoon.
Floren's first bogeys of the week on the fifth and sixth dropped him back to six under par and allowed Uihlein to move into the lead with birdies at the 13th and 15th.
At eight under par he led by one from Olazabal, who had birdied the 17th and 18th to reach the turn in 33, and Spanish Open winner Raphael Jacquelin, who had rolled in a hat-trick of birdies from the 13th.