Graeme McDowell fired a three under par 67 to make the cut with a stroke to spare but Seamus Power and Pádraig Harrington bowed out of the Honda Classic at the halfway stage in Florida.
McDowell dropped just one stroke in a solid second round on the Champion Course at PGA National in Palm Beach Gardens — a three-putt from nearly 40 feet on the 17th, his eighth.
But having opened with back to back birdies at the 10th and 11th, he picked up birdies at the par-five third and the tricky fourth to end the day tied for 48th at one-under par.
The key to the 37-year-old's score was accuracy from the tee and while he was 43rd for strokes gained putting, he made four putts outside 10 feet to undo the damage of Thursday's two-over-oar 72.
Crucially, two of those putts were for pars: a 19-footer at the 18th and a 12-footer at the tough sixth, where he drove into a fairway bunker but got up and down from 138 yards for his four.
Despite his heroics, the Portrush native is eight strokes behind co-leaders Ryan Palmer (66-65) and Wesley Bryan (64-67), who lead by one stroke on nine-under-par from Rickie Fowler (66-66) with India's Anirban Lahiri alone in fourth on seven-under (65-68).
The cut fell at level par which meant a cruel exit for Power on his Honda Classic debut after rounds of 68 and 73.
The West Waterford man Power got off to a poor start by covering the back nine, his opening nine, in a damaging, four-over 39.
After a bogey at the 10th, he missed two good birdie chances from six and 12 feet at the 11th and 13th, then took three to get down from 70 feet at the 14th and slipped back to level for the tournament.
When he double bogeyed the first hole of the Bear Trap, the 15th, by finding water from the tee, he was outside the cut line.
And while he fought back well, covering the front nine in one under, he ended up one shot shy of the cut mark on one-over par.
Harrington was still struggling for distance because of the trapped nerve in his neck and was stepping into his shots by planting his left foot on his downswing in an attempt to get more distance.
The 45-year-old — winner of the title in 2005 and 2015 — had a couple of early birdie chances at the second and third but missed putts of eight and 15 feet.
He drove into a fairway bunker at the fourth and didn't make par, then shed another shot at the 204-yard fifth, where he shoved his tee shot into the right rough and failed to make the green with his recovery.
Clearly struggling to generate power, he did brilliantly to make par at the sixth, where he had 222 yards to the pin after a 249-yard drive into the right rough.
But he played a fine recovery to within 40 yards of the pin, then hit one of his trademark pitches to six feet and holed the putt.
Attempting a cut with a fairway wood from the tee at the eighth, he came up well short in the left rough and dropped another shot after failing to get up and down from the rough short of the front right fairway bunker.
Now five-over-par for the tournament, the three-time major winner needed to come home in 30 to make the cut but managed only a level par nine of 35.
Birdies at the 10th (eight feet) and the 18th (two putts from 38 feet) were offset by bogeys at the 13th and 17th.
For once, Harrington's scrambling couldn't save him. Having missed ten greens, he could only salvage par on five occasions, well below his average strike rate of around 66%.
Ranked first on the PGA Tour for strokes gained around the greens and very solid inside five feet, he's had little luck on the greens from distance this year, holing just one putt outside 25 feet so far.
His priority now after missing the cut in four of his first five starts of the year is to decide quickly for or against surgery on his neck injury.
A lengthy layoff now will be better in the long run as sacrificing chances to qualify for the Masters or the US Open will give him time to recover for the Irish Open in Portstewart and his return to Royal Birkdale for The Open, where he won his second major in 2008.