Woods escaped with a very lucky bogey on his last hole
US unless stated
-9 Tiger Woods
-8 Davis Love III
-6 A Scott (Aus), J Furyk
-5 E Els (SA), Lucas Glover, Kevin Stadler
-4 L Donald (Eng)
-3 Stewart Cink, Robert Gamez
Reigning champion Tiger Woods was involved in chaotic scenes at the end of his second round in the WGC-Bridgestone Invitational in Akron.
Woods' second shot from the rough at the 9th, his last, flew over the grandstand and bounced onto the roof of the three-storey clubhouse.
But after 45 minutes officials gave him a free drop and he secured a bogey.
Woods said: "I don't know how that wasn't out of bounds first of all and I also don't know how anybody found it."
Woods's good fortune - he only just missed his long par putt - helped him to a round of 64 and a nine-under total of 131, a one-shot lead over Davis Love III and three clear of Australia's Adam Scott and Jim Furyk.
I did once hit into a portaloo - a guy opened the door at the wrong moment
It initially seemed the world number one, who is chasing a fourth straight PGA Tour title, would have to play his fourth shot from the same spot in the rough from where he played his wayward second.
But when a member of the clubhouse catering staff found the ball a US Tour rules official decided the clubhouse at Firestone Country Club was not out of bounds.
The Open and USPGA champion was then given a very favourable drop with an unimpeded line into the green.
Asked afterwards if he thought it was an oversight the clubhouse had not been made out of bounds, Woods said: "I'm not complaining.
"The ball was apparently in some guy's pocket and they ended up getting it.
"If I had had to re-drop from where I hit the second shot, it would have been tough to make six. It's a huge break to make five.
"I've never seen anything like it and certainly never experienced anything like it. But I did once hit into a portaloo - a guy opened the door at the wrong moment."
Europe's Ryder Cup hopefuls fared less well.
While Luke Donald tied for eighth on four under, Lee Westwood slumped to joint last place on 12 over before staging a fightback.
Ian Poulter, also needing top six on Sunday to force his way into the automatic qualification places, battled back from two over after 18 holes to level par after 36 - still only good enough for 25th.
David Howell, still in some discomfort from the shoulder injury he suffered at the USPGA last weekend, slumped from fourth to 46th. The European Order of Merit leader finished with a 79 to slide to six over for the tournament.
Dubliners Padraig Harrington and Paul McGinley, eighth and ninth in the Ryder standings, were five over and nine over respectively.
Their cup places are not secure yet and 10th-placed Jose Maria Olazabal has the chance to overtake both Irishmen. The Spaniard is two under at the halfway stage.