(CNN) -- Rory McIlroy began a fresh bid to topple Luke Donald as world No. 1 with a challenging four-under-par 66 in the Honda Classic in Florida Thursday.
The Northern Ireland star briefly held the early clubhouse lead until U.S. Ryder Cup captain Davis Love III carded a six-under 64 to tie the course record.
The 47-year-old Love, who insists he will play against Europe in Chicago in September if he qualifies, did his cause no harm with a hole in one at the 217-yard fifth and finished with a birdie at the last to open up a two-shot lead on the field.
But most eyes in the morning play were on Rory McIlroy, who had PGA Championship titleholder Keegan Bradley and Kyle Stanley in his three-man group.
McIlroy was beaten by Hunter Mahan in the final of the WGC World Match Play Championship last Sunday, denying him the top spot in the global rankings.
But victory at PGA National this week will guarantee he does go to No. 1 for the first time, and he started in fine style. Birdies at the 14th -- his fifth hole of the day -- 12th and 18th took him to the turn in 32.
Further birdies came on the second and seventh, but he three-putted the eighth to drop his only shot of the day.
"Any time you shoot 66, you have to be pretty happy," he told the official PGA Tour website.
Bradley also played well for a three-under 67 to stay in contention after the first round.
But Tiger Woods had to battle a cold putter in his one-over par 71 in the afternoon play, which left him tied for 68th and battling to make the cut.
The former world No. 1 needed 34 putts during his round despite hitting 15 greens in regulation, while third-ranked playing partner Lee Westwood finished on level-par 70.
"I didn't get a whole lot out of my round," Woods said. "Obviously I'm going to have to score better than I did today. Hopefully shoot something in the 60s and get myself within touch of the lead.
"A round I should have been probably two or three under par quickly turned into one over. I felt like I played a lot better and I putted a lot better. I just didn't score.
"Also, I didn't get up-and-down a couple times, a couple easy up-and-downs. I blew those."
England's Ian Poulter was due to be the third member of the group but pulled out due to a high fever, later diagnosed as pneumonia.
He was replaced by Miguel Angel Carballo of Argentina.
Donald, who topped the money lists in Europe and on the PGA Tour last season, is not playing at the $5.7 million tournament at Palm Beach Gardens.