Rory McIlroy backed up a fine first round with another impressive showing to ensure that he'll enter the third round of the Open just three shots behind leader Cameron Smith.
The Australian shot an eight-under-par second-round 64 at St Andrews to reach the halfway point of the final major of the year on 13-under.
His 36-hole aggregate of 131 was a new record for an Open at the Home of Golf.
For long stretches of Saturday it looked like Smith may be able to chisel out a sizeable lead but round one leader Cameron Young dug in to finish two shots back with McIlroy and Viktor Hovland a further shot behind on 10-under.
The next Irish name on the leaderboard is a surprise one, qualifier David Carey who is five-under, while Shane Lowry is a shot behind after responding to a double bogey at 16 with birdies at the two final holes.
There was disappointment for Seamus Power at his first Open though as he carded a 75 to finish on four-over par, four shots outside the cut-line.
It's McIlroy who will head the Irish charge heading into the weekend. He gave himself a look at birdie on nearly every hole, but his putter was cold in the early stages and the Holywood man cut a frustrated figure.
That looked set to continue on the par-five fifth after McIlroy’s approach was a club short after a massive drive, but he managed to sink his birdie putt to kick-start his round.
Four more birdies would arrive between the seventh and 12th holes, but a bogey at the eighth hole had left him six shots off the lead for a brief stage.
Another shot would fall at the 15th after a sloppy close-range putt, but he nailed a fine effort at the 17th, playing tricky on Friday, for an important birdie on the Road Hole.
McIlroy had one last look at a birdie on 18, but his putt skipped by and he had to be content sitting on 10-under.
"I'm picking holes in everything and walking off thinking I could have been a couple better, but I'm in a great position going into the weekend," McIlroy told Sky Sports.
"Cam Smith has been playing well this year and so has Cameron Young. Both phenomenal players; a great leaderboard with DJ (Dustin Johnson) and Viktor Hovland there.
"It's going to be a great weekend and it is nice to be in the mix."
Dublin’s Carey produced a stunning second-round 67, good enough for a spot inside the top 20.
Carey, a qualifier winner at Fairmont St Andrews, carded his first birdie at the second hole and collected another five along the way with a bogey at the sixth providing the only blemish on his card.
That left the Castleknock native, who once shot a 57 on the third level Alps Tour, on five-under-par heading into the weekend’s action, six shots behind Cameron Smith who was sitting on 11-under as the Irishman finished his round.
Padraig Harrington had managed to get to five-under early in his round too, but disaster struck as he dropped four shots between the fourth and sixth holes, three-putting for a double bogey on the last of those.
In the end Harrington would finish with a disappointing 78 to end his tournament on three-over-par, well outside the cut line.
Ronan Mullarney will also miss the weekend after a second-round 78 left him on seven-over-par.
He only managed one birdie on the front nine after driving the green at the par-four ninth, with his back nine producing six pars and three bogeys.
Darren Clarke was always in trouble after his first-round 79, but he did improve in round two with a 75 – back-to-back birdies at five and six the highlight as he finished on 10-over.