PALM BEACH GARDENS, Fla. — Confidence in his golf game was how Rory McIlroy turned a not-so-smooth start into a 4-under-par 66 on Friday to hold on to his lead midway through the Honda Classic.

After an opening 63, McIlroy started Friday on the back nine and bogeyed the 11th and 12th holes, but birdied Nos. 16 and 18 to return to even par for the day.

Four birdies in a five-hole stretch on the front had him at 11-under-par 129 and a shot ahead of Brendon de Jonge, who followed an opening 66 with a 64 on the Champion Course at PGA National Resort & Spa.

Russell Henley, who began the day in second place after a 64, was third at 132 after a 68.

Russell Knox had the lowest round Friday, a 63 with seven birdies that had him tied for fourth with Lee Westwood, who shot 65, at 133.

Tiger Woods shot 69 to make the cut on the number at even-par 140. Phil Mickelson had a 71 to finish at 141.

“It wasn’t the start that I wanted to get off to,” McIlroy said. “But I stayed patient, made a couple of good birdies before the end of the front nine and then played really, really good on the back and holed a couple of really nice putts.”

A native of Northern Ireland who has a home a few miles from PGA National, McIlroy, 24, said the way he finished out his front nine was the key to how he played his back nine.

“I holed a good 4- or 5-foot putt on 14 for par, and then I holed a great putt on 18, which gave me a little bit more of a spring in my step going to the back nine,” said McIlroy, who sank a 12-footer for birdie on 18.

McIlroy’s putting has been exceptional. He had 25 putts Thursday and 24 Friday, which he said might be the fewest total putts he’s ever had after 36 holes. He attributed the improved putting to a visit last week with Dave Stockton.

“We tweaked a couple of things,” McIlroy said. “All of a sudden yesterday it started to feel very, very comfortable.”

He’s also thinking smarter. After those two early bogeys, he said he realized that a few bogeys are inevitable in a 72-hole tournament and he also knew that there were some birdie holes ahead of him.

“I had two par 5s that were reachable, a couple of short par 4s,” he said. “So I knew with the way I’m playing and the confidence in my ability, I would be able to get those shots back.

“I didn’t panic. I didn’t try to do anything different. I just tried to keep playing the way I was.”

Putting was a key for de Jonge, 33, of Zimbabwe, who has never won on the PGA Tour.