Brian Keogh in Miami

Who’s afraid of the big Blue Monster? Not Rory McIlroy it would appear after the teenager produced another fearless display at the famed Doral lay-out to caress what could be a historic victory in the WGC-CA Championship.

If the 19-year old from Holywood lifts the Gene Sarazen Cup here tomorrow night, not only will he pocket a cheque for $1.4 million, he will also become the youngest winner in the history of the PGA Tour.

Johnny McDermott claimed the US Open at the tender age of 19 years, 10 months and 14 days in 1911. But after finishing eagle-birdie to post a sensational six-under par 66, McIlroy is just three strokes adrift of leader Phil Mickelson in a share of third place with Kenny Perry on 10-under par and in line to beat McDermott’s record by two days.

The young Ulsterman has amazed American golf fans, not just with his game but also with his cool and his playing partner Jim Furyk, the 2003 US Open champion, believes that the hottest ticket in world golf has “scary” potential

“His maturity is what impresses me most,” said Furyk, who is five strokes off the pace on eight under par after a second successive 68. “He is going to be a hell of a player. He already is now. It is scary what the potential is.”

Padraig Harrington produced a Jeckyll  and Hyde performance - zooming to four under par for his round after five holes thanks to an eagle three at this opening hole (the 10th) and birdies at the 12th and 14th.

His Ferrari-like start left him just one stroke behind early leader Prayad Marksaeng on ten-under par. But he played his remaining 13 holes in three-over par and signed for a 71 that relegated him to a share of 15th place on seven-under par.

The Dubliner confessed that the good luck that accompanied him in Thursday’s first round 66, turned its back on him on Friday 13th and he paid the maximum penalty for his mistakes as every errant shot finished in water or unplayable in the trees.

“It was similar in that I struggled off the tee,” Harrington said.  “Everything went right for me yesterday and everything went wrong today. We got to the stage today where I hit a bad shot and we were walking down there, nearly expecting the worst and it kind of became comical.   I seemed to get every bad break going out there."

McIlroy, it seems, can do no wrong and he produced two career shots yesterday that left his caddie JP Fitzgerald almost lost for words.

Starting on the back nine, the teenager birdied the par-five 10th and 12th holes before producing an impressive sand save from the back bunker at the long, par-three 13th.

He then birdied the short, par-four 16th to get to within four of the lead on seven under par before producing just the fourth birdie of the week at the fearsome, 467-yard 18th with what he described as one of greatest shots of his career.

Playing in a stiff wind, McIlroy drilled a 263-yard drive down the right side of the fairway and then unleashed a perfect four-iron from 206 yards that pitched beside the stick and danced to a halt just six feet from the hole before tossing the club back to his caddie.

After watching his young boss roll in the putt, caddie Fitzgerald walked off the green and said: “That’s the best shot I’ve ever seen in my life.”

But he would see an even better shot at the tail end of a round that McIlroy will remember for some time to come.

Having picked up another shot at the par-three fourth, where he rolled home a 22 footer, McIlroy three-putted the fifth and failed to get up and down from sand at the seventh to slip back to seven-under par.

His response was stunning. Faced with a 268 yard second shot over water to the eighth, he fearlessly drilled a three wood to ten feet and rolled in the putt before knocking a seven iron to four feet at the par-three ninth.

“I just made two bad bogeys to drop back to seven under and I just ripped a drive up the fairway and I had 268 to the hole,” McIlroy said of his eagle. “It was a perfect three wood for me.

“They were the two best shots I think I've ever hit to be honest.  That four‑iron on 18 was up there, as well.  Two great shots today, and, you know, it's nice to convert both of them.”

There will be no change of strategy over the weekend either.

“It's the way I play,” McIlroy said.  “I get a kick out of it when I'm trying to go for greens and trying to go for pins over water and I’ve got a great chance now over the weekend.”

Tiger Woods posted a two-under par 70 to trail Mickelson by 10 shots on three-under par. 

Woods said: "Today felt a lot better than it did yesterday and yesterday felt a lot better than it did in Tucson. I'm starting to get a feel for being in that environment again, and it's starting to feel better and better."

Darren Clarke hit a one under par 71 to get back to one-over par for the championship but Graeme McDowell is languishing near the back of the field on three-over after a disappointing 74.