Leading by four strokes at the start of the day, Rose saw his advantage evaporate completely when he bogeyed the first and double bogeyed the second hole in his head-tohead with the Dubliner.

But the 27-year-old Englishman kept his composure to play the remaining holes in three under par, card a level par 71 and take a four-stroke advantage over Harrington (71) and Simon Dyson (69) into the final round. Harrington will play in the second last group with Germany's Martin Kaymer (66), knowing that he must finish ahead of Rose and inside the top three to retain the Harry Vardon Trophy.

"It's in his hands tomorrow, " Harrington said afterwards. "Four shots behind is a lot of ask going into the final round so I am a little disappointed. I needed to be a little better. I was trying to focus on my own game, I was probably too aware of what he was doing and I am quite happy that I am not in the same group and I will be doing my own thing tomorrow and not watching what he is doing.

"Any hole can yield a birdie or a double bogey. A lot can change very quickly. It is a long tough grind but Martin Kaymer shot five under today so a good score can be had."

It took Harrington just two holes to eat up Rose's four stroke overnight lead, threading his approach through the branches of a cork oak at the first and holing from 12 feet for a miraculous birdie as the Englishman three-putted from the apron.

Rose then clattered into the TV gantry behind the second green and duffed two chips from deep rough before two putting from 12 feet for a double bogey six.

The gap was just two shots again at the turn, however, as Harrington mixed a bogeys at the fourth and seventh with a birdie at the fifth while Rose steadied the ship to birdie the eighth and went on to play majestically on the back nine.

With his early hiccups behind him, Rose birdied the 10th from 35 feet and 11th from five to regain his four stroke lead on four under par.

Harrington drove into the trees at the 13th to drop another shot and fall five behind on one over par but bravely holed from five feet at the 17th to cut the gap to four shots once more and set up a heart stopping final day.

"It was a heart attack start, " said Rose, who saved par from eight feet after a visit to sand at the last. "I had a sand wedge and a pitching wedge on those first two holes and made a five and a six.

Not to drop a shot for the rest of the day was pretty unbelievable.

"I won't be changing anything tomorrow. Padraig is a fighter and he proves it. He digs in deep and never gives in. As I proved today, four shots is nothing round here and I have to play well."

Graeme McDowell slipped back from joint third to eighth after three over par 74 that was marred double bogey seven at the par-five 17th while Paul McGinley hit a 74 that dropped him from seventh to 10th on five over par.