Rory McIlroy insists his confidence is on the rise after he regained his driving mojo and opened with a four-under 68 in the Farmers Insurance Open at Torrey Pines.

Despite making a near 14,000 km trip from Abu Dhabi to San Diego for his first PGA Tour start of the year, the world number seven raced to the turn in four-under 32 on the South Course that will host June’s US Open, then came home in level par to finish the day tied for 21st on four-under-par. Scores

It might have been a lot better for the Co Down star (31), who failed to birdie the two-par fives on the back nine and three-putted the 15th after a poor wedge before getting that shot back at the 17th.

He finished the day four strokes behind former Masters champion Patrick Reed and Sweden’s Alex Noren, who shot eight-under 64’s on the easier North Course to lead by a shot from American Scottie Scheffler, who also played the North.

But he was still pleased to see his driving game back to its best after an erratic final round performance cost him the Abu Dhabi HSBC Championship on Sunday and optimistic for the future after seeing signs of a return to top form late last year.

“I feel like it was a little bit of a tale of two halves,” said McIlroy, who birdied the second and third before picking up birdie fours at the sixth and eighth. “I played the front nine really well, played that in four-under, but I guess a little disappointed that I didn’t pick up any more coming in, especially with the par-fives 13 and 18.”

Preferred lies were in operation as officials braced themselves for wind and rain on Friday but McIlroy, who missed just one green in regulation and led the field for driving distance, strokes gained off the tee and greens in regulation.

“I dropped a shot with a bad decision, a bad approach on 15 but got it back on 17. So I think when you start this tournament on the South Course, you just want to get off to a decent start, especially today, knowing that the weather is going to come in tomorrow, which will obviously make the South Course even tougher. I am satisfied. I wish I could have got a couple more but you are never going to complain shooting four-under out there.

He determined to commit to his tee shots and admitted he gained in confidence after what was a hit and miss performance in the UAE, where he finished third, five shots behind Tyrrell Hatton.

“It gives me a lot of confidence, especially with how I drove it parts of last week,” McIlroy said. “It wasn't very good, it was a little guidey at times. First tournament back out, maybe a little unsure of what I'm doing. I made a decision today that I'm just going to fully commit to every swing I make off the tee, and it worked, I hit some great tee shots, took advantage of some of them. Didn't take advantage of some others on the back nine, but I was happy with how I hit it out there.”

Set to play seven tournaments in 10 weeks before the Masters, he feels comfortable that his game is back on track after enduring a loss of form last summer when golf resumed without fans.

“I’m very optimistic,” he said. “I think in this game you need to be an eternal optimist. You can’t get down on yourself too much. I was very encouraged with the play I showed at the back end of last year, getting to see my swing coach Michael Bannon a little more. I saw him just before Christmas and he was with me in Abu Dhabi last week.

“All those things combined, just showing a little more form, I am pretty happy where the game is and very optimistic going into these next few weeks.”

It was a far tougher day for West Waterford’s Seamus Power, who got into the event as first alternate late in the afternoon but he had three three-putts in a 78 that left him tied 147th on six-over.

The Tooraneena man (33) was called in as a late replacement for Scott Piercy, but he immediately bogeyed the 10th, three-putted the 12th for a double-bogey and then bogeyed the par-five 13th after hitting his approach into a hazard.

He steadied the ship around the turn but three-putted from seven feet for a double-bogey at the short third, then three-putted the fifth from 50 feet before chipping dead to birdie the long sixth.