Tiger Woods shot a four-under-par 68 to take a one-stroke lead into the third round of the Target World Challenge.

The world number one, who hosts the event, shot his second consecutive 68 to move to a eight-under 136 at Sherwood Country Club in Califirnia and be on track for his third victory in eight years.

Woods split a pair of birdies on each nine to surge past Henrik Stenson, the first-round leader who followed his opening 66 with a one-under 71.

But Woods, who admitted that he was still struggling to find the pace of greens, didn't deny that Lady Luck had helped him edge in front

"Yes, I had two lucky breaks," he said

Trailing by four shots as he approached the turn, Woods hit a 40-foot birdie putt on the ninth hole that looked as though it would run right through the green and off the other side - until it slammed into the back of the cup, and jumped high in the air before dropping into the hole for birdie.

But that wasn't the end of it.

One hole later, a birdie putt even longer, was also picking up a fair head of steam when it also hit the back of the cup with force and dived into the hole.

Fanny Sunesson, Stenson's caddie, could only turn her back and smile in disbelief when the second putt disappeared.

Stenson was nowhere near as supervised. He has played often enough with Tiger to know better.

"I think the putting and his trouble shots are probably the two things I admire the most about his game and I know there's always going to be one or two long ones finding the right line," Stenson said.

"He threw both at nine and 10. It's no surprise anymore that he makes those kind of putts."

Padraig Harrington fired an impressive 67 to move within six of Woods' lead and is tied with Colin Montgomerie (73) and David Toms (69) on two under.

Paul Casey is alone at five-under 139 while John Daly and Jose Maria Olazabal are tied at 140.

Adam Scott tumbled to an 80 and fell into last place at 11-over 155.

Collated second round scores & totals

(USA unless stated, par 72):

136 Tiger Woods 68 68

137 Henrik Stenson (Swe) 66 71

138 Chris DiMarco 70 68, Geoff Ogilvy (Aus) 68 70

139 Paul Casey (Eng) 69 70

140 John Daly 69 71, Jose-Maria Olazabal (Spa) 70 70

142 Colin Montgomerie (Sco) 69 73, David Toms 73 69, Padraig Harrington (Irl) 75 67

143 Michael Campbell (Nzl) 74 69, Fred Couples 69 74

146 David Howell (Eng) 71 75

147 Davis Love III 77 70

150 Luke Donald (Eng) 76 74

155 Adam Scott (Aus) 75 80