Darren Clarke's hopes of succeeding Padraig Harrington as winner of the Irish Open nosedived after a closing triple-bogey eight at Adare Manor.
Two off the lead of Welshman Bradley Dredge on the tee of the par five, the Ulsterman pushed his drive and, unable to go for the green, hit his second into a bunker.
He still had River Maigue to negotiate for his next shot but sent the ball flying over the green out of bounds.
Dropping another ball back in the sand, he just chipped out and took three more to slump from six under par to three under.
Defending champion Harrington had an up-and-down round of 70 to finish up on three under, six strokes off Dredge's leading total of nine under par.
Rory McIlroy and Gary Murphy are best of the Irish at four under par, while Paul McGinley lies on one under, with Peter Lawrie back on two over.
Meanwhile, Lee Westwood produced one of the greatest finishes to a round in European Tour history, following birdies at the 14th, 15th, 16th and 17th with a closing eagle three.
Six under for the last five holes gave the former European number one a 64, only one outside Harrington's course record, and he went into the final round in third place, two shots behind leader Bradley Dredge of Wales.
In terms of scoring, the only finish that can better Westwood's on the circuit came from Australian Peter O'Malley on the final day of the 1992 Scottish Open at Gleneagles.
O'Malley went eagle-birdie-birdie-birdie-eagle to pip Colin Montgomerie to the title.
Westwood was only playing in Ireland because he fell ill three weeks ago and pulled out of the Wachovia Championship in America.
‘I just went out to enjoy it today - and that was very enjoyable,’ he said. ‘It was great.
‘A 64 round here, you have got to class as a pretty good score. I pulled the four-iron at the last, but it was a good putt.’
Having already rolled in a 15-foot eagle putt on the seventh in an outward 33, Westwood was cursing when he took six at the long 12th after reaching a greenside bunker in two.
‘You hate that and frustrating would be a nice word to use,’ he added.
But two holes later he converted a 10-foot chance, then holed putts from 20 and four feet before chipping in at the 17th and making the 12-footer on the 548-yard last.
It made him leader on his own at the time, but Finch then birdied the 15th and 18th to get in on eight under.
