By Phil Casey, PA Sport

Colin Montgomerie went from ecstasy to agony with another Jekyll and Hyde performance on an amazing third day of the Open championship at Muirfield.

A day after his lowest-ever Open round of 64, the former European number one slumped to a 13-over-par 84, his worst-ever in the Open by eight shots.

It was the joint biggest variation between two rounds in championship history, equalling the 20-stroke difference between RG French's second round 71 and third round 91 in 1938.

Almost incidentally, it left the 39-year-old nine over par for the tournament and one shot off last place, after starting the day just two off the lead.

It has been an incredible rollercoaster performance all week from Montgomerie, who labelled his opening 74 "awful", and claimed he would be struggling just to make the cut.

Less than 24 hours and a change of clubs later, he roared back into contention with a course record 64 and suddenly the doom and gloom of the previous day was forgotten.

"I have to keep this momentum going and not let this go," Montgomerie said.

"I know I can win. I've never been frightened of winning and I'm not frightened of winning here."

It was not to be, however, despite a solid start amidst the worst of the weather when the rest of the leaders were being blown off course.

Things soon started to go awry though and he dropped his first shot of the day on the fourth after finding a greenside bunker on the par three.

A bogey on the next followed but it was probably one of the best of his career. He found rough off the tee and appeared to have a dreaded "shank", the ball scuttling across the fairway into more trouble.

From there he hacked onto the fairway and needed to hit a driver for his fourth shot, drilling it onto the green and doing well to two-putt from long range for a six.

A fairway bunker brought more trouble on the next and he need to hole from 35 feet for that, but there was no such escape on the eighth where he ran up a six.

A par five on the ninth took him out in 41, bad enough, but worse was to follow despite the wind dropping and the rain stopping.

Another double bogey on the 10th was followed by three bogeys in succession and three more to finish, and not surprisingly he was in no mood to share his thoughts on the round.

From ninth to joint 79th, Montgomerie had seen another chance for that ever elusive major title thrown away, and time is running out to rid himself of the dreaded tag of 'best player not to have won a major'.