|Irish Open second round leaderboard|
|-8 M Warren (Sco), D Willett (Eng); -7 R McIlroy (NI); -5 M Southgate (Eng); -4 J Van Zyl (SA), R Sterne (SA), T Hatton (Eng)|
|Selected others: -3 J Donaldson (Wal); -2 M Kaymer (Ger); -1 G McDowell (NI)|
Rory McIlroy remains in contention to win a first Irish Open title after a second-round 70 left him a shot behind leaders Danny Willett and Marc Warren.
Scotland's Warren fired a six-under 66 at the K Club to join overnight leader, Masters champion Willett - who had four bogeys in a 71 - on eight under.
Northern Ireland's McIlroy, who started his round on the 10th, closed with a birdie on the ninth.
England's Matthew Southgate is fourth on five under after a three-under 69.
Warren had seven birdies in his 66 and the 35-year-old, who is yet to record a top-10 finish on the European Tour this season, showed signs of recapturing the form which took him into the world's top 50 for the first time last year.
"For the first few months of the year it's been a bit stop-start but we're getting into more of a run now and hopefully that continues," added Warren, who has missed the cut in five of his last seven starts.
McIlroy 'excited' to be in contention
After missing the cut in his home event for the last three years, McIlroy, 27, said he was "excited" to be in contention at the halfway point despite some erratic play on Friday.
"I gave myself plenty of chances and took care of most of the par-fives but made too many mistakes," said McIlroy, whose Rory Foundation is hosting the tournament.
"I missed a few more greens because I missed a few more fairways, so I need to tidy that up - but 70 was not a bad score this morning.
"To have the Masters champion and me both up there - it's shaping up to be a great weekend."
McIlroy is seeking a first win of the season after six top-10 finishes.
Willett unable to reproduce first-round heroics
Willett, 28, was unable to reproduce his first-round heroics despite again getting the best of the weather conditions.
"It wasn't bad - a little bit scrappy," said the Englishman.
"It was windy at times and there were a couple of sneakier flags out there as well, so you can't come off being joint leader and be too unhappy."
The 2012 Irish Open champion Jamie Donaldson finished on three under in a group that includes English trio Eddie Pepperell, Chris Wood and Callum Shinkwin plus Scotland's Richie Ramsay.
Graeme McDowell is seven off the pace on one under after a 72, while European Ryder Cup captain Darren Clarke made the cut after a 71 put him on level par.