Rookie Luke Guthrie leapt to the top of the Honda Classic leaderboard on Friday, but his ascent was overshadowed by the withdrawal of world No. 1 and defending champion Rory McIlroy.
After carding a pair of bogeys, a double bogey and a triple bogey in his first eight holes, McIlroy dumped his approach in the water on No. 18, shook hands with playing partners Ernie Els and Mark Wilson, and walked off the course.
The world's top player later cited a sore wisdom tooth as the reason for his early exit, adding that the molar is "due to come out in the near future."
"(The tooth) began bothering me again last night, so I relieved it with Advil. It was very painful again this morning, and I was simply unable to concentrate. It was really bothering me and had begun to affect my playing partners. I came here with every intention of defending my Honda Classic title. Even though my results haven't revealed it, I really felt like I was rounding a corner," McIlroy said in a statement.
Thus continues a disappointing opening stretch for McIlroy, who suffered a cut at the Abu Dhabi HSBC Golf Championship and a first-round loss to Shane Lowry at last week's WGC - Accenture Match Play Championship in his only other starts this season.
Tiger Woods, who finished runner-up to McIlroy at this event last year, shot 70 for the second consecutive day to finish just inside the cut line at even par.
The world No. 2 flirted with the line throughout the day. Sitting at 1-under through nine, Woods found a fairway bunker and then a greenside bunker on the par-4 13th and carded a double bogey. He rebounded with a birdie at No. 14, and then gutted out four straight pars to make it to the weekend.
"Well, I didn't hit it anywhere near as good as I did (Thursday)," admitted Woods. "I didn't have it today."
Now on to the top of the leaderboard, where the 23-year-old Guthrie fired a 7- under 63 with the morning wave to move in front.
The 63 marked a PGA Tour career-best for Guthrie, who sits at 9-under 131 through 36 holes -- good for a 1-stroke lead over Michael Thompson, who carded a 65.
"I was really hitting good, crisp shots, firing at flags, and I felt like I could have shot 5-under yesterday pretty quickly," said Guthrie, who shot 68 on Thursday. "I was pretty excited to get back out here and kept it rolling."
Boo Weekley (67) and Graham DeLaet (68) are tied for third at 7-under, while Lee Westwood (68), Justin Rose (66), Charles Howell III (67), Geoff Ogilvy (66), Sean O'Hair (68) and Doug LaBelle II (68) are all a shot back.
The world No. 9 Westwood, who recently moved close to PGA National, has finished in the top 10 at this tournament in two of the last three years.
Graeme McDowell (68) is one of seven players tied for 11th at minus-5, while Keegan Bradley (68), Rickie Fowler (71) and Branden Grace (71) are part of a group knotted at 4-under.
Overnight leader Camilo Villegas stumbled to a second-round 77 and missed the cut. Seeking his first PGA Tour victory since winning this event in 2010, the Columbian carded five bogeys and a double bogey on Friday and finished at 1- over.
Thompson tallied six birdies against a single bogey on Friday and found the clubhouse in sole possession of first place, but Guthrie was poised to strike.
One stroke off Thompson's pace through 14 holes, Guthrie tallied consecutive birdies at Nos. 6 and 7 to go in front at 9-under. The rookie capped his bogey-free round and stayed on top with pars on the eighth and ninth.
Earlier, Guthrie kickstarted his day with a run of three birdies in four holes beginning at the 12th. Later, he picked up shots at Nos. 1 and 3 to get within striking distance.
"I'm pumped for it," Guthrie said of playing in the final group on Saturday. "I don't think I've got to the final group yet. I was about three groups off at the John Deere last year I think. I can't wait for that."
NOTES: Guthrie's previous best round was 64 in the last round of the 2012 John Deere Classic and in the third round of this season's Humana Challenge ... Villegas was playing in this tournament on an exemption after finishing outside the top 125 on the money list last season and losing his card. He has missed three straight cuts ... Robert Allenby missed the cut at 2-over, but he did manage to pick up a hole-in-one on the par-3 seventh ... Last year, McIlroy shot four rounds in the 60s and finished the championship at 12-under 268. That was enough for a 2-shot victory over Woods and Tom Gillis.