Tiger Woods takes a seven-shot lead into the third round of the WGC Bridgestone Invitational, but was entitled to be disappointed not to be even further in front.
Nine under par after 13 holes of his second round at the par-70 Firestone Country Club, Woods needed to play the last five in two under to record only the sixth 59 in PGA Tour history.
However, after scrambling a par on the 14th, good birdie chances went begging on the 15th and 17th and the world number one eventually had to hole from 25ft for par on the last.
A flawless 61 containing seven birdies and an eagle equalled the lowest round of Woods' career and left him an overwhelming favourite for an eighth win at Firestone and 79th PGA Tour title, three behind Sam Snead's all-time record of 82.
At 13 under par he held a seven-shot lead over defending champion Keegan Bradley and England's Chris Wood, who were both round in 68, with Open runner-up Henrik Stenson and American Bill Haas another stroke back.
Rory McIlroy is one over after a 71, with Graeme McDowell two over also after a 71. Shane Lowry is eight over.
"He is a very intimidating guy but I just have to play 18 holes, enjoy the experience and try to beat him" - Chris Wood
Asked about the prospect of shooting 59, Woods said: "I certainly could have done it, I've done it before (in practice at his home course of Isleworth).
"I felt pretty relaxed with it. If I hadn't shot 59 before it would have been a different story. I was only nine under, so it's not a feeling that I'm uncomfortable with.
"When I shot 59 I was 13 deep at the time, so that's well off where I was today. Nine, I've been there many times, and I've been 10 and 11 before, too. I had five holes to go, still a lot of golf to be played, and anything could have happened. It could have gone either way."
Two shots off the pace after an opening 66, Woods holed from three feet for a birdie at the first, 20ft for eagle at the second and 12ft for birdie at the third to vault into the lead.
A birdie on the seventh took him out in 30 and history beckoned when he started the back nine with four straight birdies, but in the end he could only manage five closing pars.
Wood, making his debut in the event courtesy of winning the Qatar Masters in January, carded four birdies and two bogeys in his 68.
The second of those dropped shots came on the 18th and cost him outright second, but with play switching to threesomes on Saturday due to forecast bad weather, the 25-year-old would still play in the final group with Woods and Bradley.
Asked about playing with Woods on Saturday, Wood told Sky Sports: "I have grown up watching him and it will be a dream come true to play alongside him.
"He is a very intimidating guy but I just have to play 18 holes, enjoy the experience and try to beat him."