Saturday in Jerez, Spain, Clarke played his final three holes in 3-under-par to tie overnight leader Pierre Fulke for the 54-hole lead at the Volvo Masters, and, in the process, put himself in prime position to overtake Lee Westwood for the top spot on the Volvo Order of Merit.
Clarke fired a 4-under-par 68 to move to 11-under through three rounds, the same number reached by Fulke, who birdied the home hole for a 2-under-par 70.
Stephen Leaney is in solo third place at 10-under after a third-round 69. Jose Maria Olazabal stands in a four-way tie with Ricardo Gonzalez, Angel Cabrera and Fredrik Jacobson for fourth place at 8-under. The Spaniard could only manage an even-par 72 on Saturday.
Clarke, who trails Westwood by roughly $70,000 in earnings, began the day two shots back of Fulke. The Northern Irishman got off to a hot start on Saturday, birdying three of his first seven holes, but cooled quickly, thereafter.
Clarke bogeyed three of his next eight holes to drop to 8-under-par for the tournament, and even-par for the day.
He then hit his favorite stretch of holes at Montecastillo.
Clarke eagled the par-5 16th, parred the par-4 17th, and birdied the par-4 18th. Clarke has played the final three holes in 7-under-par through three rounds.
'I said at the start of the week that I wanted to put myself into a position where I could challenge for the tournament and that's what I've managed to do,' said Clarke.
'I was very patient again today. I waited for things to happen. If I could bottle (the attitude) I've got this week I would pay a fortune for it. I don't know what's going on. This hasn't been like me.'
Saturday, Clarke played alongside the man he's trying to secede as Order of Merit champion. Needing to win this week and next to secure his eighth-straight money title, Colin Montgomerie dropped from a three shots off the lead as the day began to eight strokes back by day's end.
Monty carded a dismal 3-over-par 75 in the third round. The Scot's poor performance, combined with the Clarke's stellar play, has all-but assured the European Tour of a new money champion in 2000.
If Clarke is to come out of this week leading the Order of Merit, he'll have to fend off a surging Westwood. After opening in 76, the Englishman has fired rounds of 69-65 to climb within five strokes of the lead at 6-under-par.
Westwood carded six birdies and an eagle before finding the water on the 18th with his tee shot for his only bogey of the day. He blamed the mishap on a spectator who moved in the middle of his backswing.
'I didn't say anything to the guy,' Westwood said. 'I just gave him one of those glares - the Seve glare! The one that makes you tremble and feel like crawling into the nearest hole.'
Water also resulted in Fulke's lone dropped shot of the day. The Swede found the hazard at the 16th to fall off his perch at the top of the leaderboard. However, Fulke reclaimed a share of the lead by sinking a birdie at the 18th.
'I had a lot of chances, but the putter didn't work,' Fulke said. 'I had a nice birdie to finish from ten feet at the last, but my goal is to win the Volvo Masters which would get me into the WGC-American Express Championship next week.'