Rory McIlroy did his best Tiger Woods impression and ended his 18-month winless drought with a thrilling three-shot victory in the Arnold Palmer Invitational at Bay Hill.

After a month of mediocre form raised questions about his preparedness for the Masters in 17 days' time, the Co Down man roared back to his very best, rolling in a Woods-like 25 footer at the 18th for an eight-under 64, his 22nd career title and his 14th on the PGA Tour on 18-under-par.

“It was awesome,” said McIlroy, whose last win in the 2016 Tour Championship came on the same day Arnold Palmer passed away. 

“To feel the buzz of being somewhere around the lead going into the back nine and reeling off those four birdies in a row - I missed it. I really have missed it.

“To play the golf I played today under that pressure, I am really proud of myself and just so happy to get the win.

“I just kept telling myself to be patient and give myself looks and I did. I think I gave myself chances for birdie on basically every hole bar 15 and I made birdie there.

“I was just trying to give myself good looks at it all the time, hit fairways, hit greens and stay patient. I played a perfect round of golf."

There was a major-like frisson in the air all day as a resurgent Woods launched a final round charge to get to within one of the lead with five holes to play.

Just 10 months after his spinal fusion, a fairytale ninth win seemed possible for the eight-time winner of the event.

But while drove out of bounds and bogeyed the 16th,  dropping another shot at the 17th to shoot a 69 and a share of fifth on 10-under par, he looks like a man with the tools to challenge for a 15th major win at Augusta National.

If he's to win there, Woods (42) will surely have to deal with comeback kid McIlroy (28), who appears to have discovered the secret of good putting after yet another long sojourn in the desert.

That his 100th putt of the week came on the 72nd green is a great sign for anyone with cash riding on McIlroy to complete the career Grand Slam at Augusta National.

Back now to seventh in the world, he went into the final round two shots adrift of Henrik Stenson (fourth after a 71) after an impressive 67 on Saturday and left a slow start behind him by making three birdies in four holes from the sixth to tie for the lead.

Woods created an electric atmosphere as made six birdies and a bogey in a stunning 10-hole, mid-round stretch before his wayward drive at the 16th left the stage to McIlroy, who made four birdies in a row from the 13th and another at the 18th to etch his name on the trophy.

Having missed his second cut in four starts at the Valspar Championship the previous week,  making that early season brilliance he showed in Abu Dhabi and Dubai seem like a desert mirage, he had a putting "lesson" with the eight-time PGA Tour winner Brad Faxon (56) at the Bear's Club last weekend and arrived in Bay Hill a new man.

“I kept telling everyone I was close," McIlroy said. "No one would believe me. I wasn’t that far away. I took a lot from the two performances in the Middle East. 

“I went through a rough patch when I went to the West coast and through the Florida swing but with golf, it is never that far away.”

The key was about being more instinctive and less mechanical on the greens —"honestly, it was more of a psychology lesson rather than a putting lesson," Mcllroy said.

A change to the 34 1/2 inch putter that brought him four major wins allowed him to get comfortable over the ball and he went from the lower echelons of the strokes-gained putting charts last week to first in Orlando, knocking in six birdie putts outside 10 feet last night to finish with a strokes-gained putting tally of 10.027.

He was also first for proximity to the hole — a big turnaround on his recent form — as well as scrambling and driving distance.

Having failed to get a putt to drop early on, he was off from the moment he made an 11-footer at the 556-yard sixth.

Another quickly followed from 12 feet at the par-three seventh before a 354-yard drive took all the sting out of the ninth and he took advantage, holing confidently from 11 feet.

Stenson had hardly put a foot wrong over the opening holes, rolling in 12 footers for birdies at the first and fourth to leave McIlroy four behind.

But he three-putted the eighth to allow McIlroy to draw level and a fascinating back nine battle began with Woods the early protagonist.

Five adrift overnight, the 14-time major winner was three-under for the day and three behind as the leaders made the turn.

But he then birdied the 12th and 13th to within one and raise hopes of a dramatic comeback victory before quickly dashing them by driving out of bounds at the 16th.

Instead of Tiger, it was McIlroy who gobbled up the opposition, fist-pumping as he holed a 15 footer for a three at the 13th to lead outright before knocking in a 21-footer at the 14th to go two clear.

Stenson, Bryson DeChambeau got back to with one, but it was McIlroy who donned the Tiger-suit, chipping in for a third successive birdie at the 15th, before adding another at the 16th where a 361-yard drive set up an easy two-putt

DeChambeau eagled the 16th to get back to within one but McIlroy closed him out with that closing birdie and the Californian eventually bogeyed the 18th for a 68 and second place on 15-under with Justin Rose a shot further back after a 67

As for Graeme McDowell, he started with two birdies in his first four and finished with three in a row.

But he signed for a one-over 73 to finished tied for 22nd on five-under, dropping six shots in a nightmare 11-hole stretch in the middle of his round after twice getting into trouble in Bay Hill's difficult bunkers.

On the Sunshine Tour, Team Ireland's Neil O'Briain (31) won the Bobby Locke Trophy awarded to the Rookie of the Year despite having to withdraw from the season-ending Tour Championship at halfway with a back and hip injury.

He got last place prize money and held off American Zack Byrd by just ZAR 5,222 — approximately €355 —  finishing 43rd in the money list to earn starts in four European Tour co-sanctioned events next season.

Byrd needed to finish tied 12th or better to overhaul O'Briain but tied for 18th on three-under, 14 shots behind winner Darren Fichardt.

"It’s very cool to win the Bobby Locke Trophy because in my time at Royal Dublin, I'd see that photo in the club of Bobby Locke winning the low amateur prize at the Irish Open in 1936," O'Briain said. 

"He was 18 years of age — far more of a rookie than me — but it's nice to know you can teach an old dogs new tricks."