Graeme McDowell is out of the WGC Match Play event in Arizona after being beaten one-up by Australian Jason Day in Saturday's quarter-finals.
McDowell had earlier come through against Ireland's Shane Lowry - the man who beat world number one Rory McIlroy in the first round.
But the former US Open winner was some way short of his best and paid for some ragged play against Day.
Day's semi-final opponent is Matt Kuchar who defeated Robert Garrigus.
For Northern Irishman McDowell, two birdies in the first three holes against Day briefly gave him hope of winning though but it was not to be.
He looked at sea at times on the back nine - a loose tee shot here, a lack of finesse at the greens there and plenty of apparent frustration.
A player in better touch than Day would have put him away earlier, but as it was he took the lead for the first time at hole 11.
McDowell got back on terms at 14, lost the next hole and then rallied again at 16.
A bogey-five at 17 was the final nail in his coffin, a missed 10-footer from the sleeve of the green representing his last chance.
Day then made a two-putt to go through.
QUARTER-FINALS (USA unless stated)
Robert Garrigus lost to Matt Kuchar 3 & 2
Steve Stricker lost to Ian Poulter (Eng) 3 & 2
Graeme McDowell (NI) lost to Jason Day (Aus) 1 down
Webb Simpson lost to Hunter Mahan 1 down