Tiger Woods stunned by his own brilliant round

American takes two-shot lead at halfway stage of Zozo Championship in Japan

Leader Tiger Woods checks the line for a birdie on the 13th hole during the second round of the PGA Zozo Championship golf tournament in Inzai. AFP

Tiger Woods shocked himself with a second straight 64 for a two-stroke lead at the halfway stage of the rain-delayed Zozo Championship in Japan.

"I'm surprised that I was able to score as well as I have," admitted Woods, who is playing his first tournament for two months after having knee surgery. "It usually that takes a little bit of time. I've been able to strike my irons pretty well this week so far and that's been nice."

The 15-time Major winner lit up the back nine in five-under 31 to take control on an empty Narashino Country Club course, closed to spectators for safety after soaking up more than six inches of rain during Friday's washout.

"I had made a couple putts today and I went to put my hand up and I'm like, don't put your hand up, there's no one clapping," said Woods.

Chasing a record-equalling 82nd PGA Tour victory, Woods had bounced back from bogeying his opening three holes to shoot a mesmerising 64 with nine birdies in Thursday's first round.

He started more steadily on Saturday and was one-under at the turn before switching on the afterburners. "Hit the ball a little bit better," Woods said. "Let's hope that trend continues."

Three birdies in four holes from the 10th took him alongside clubhouse leader Gary Woodland at 10-under.

Woods kept his foot down. The US Masters champion smoked a massive drive down the long par-four 17th and his pinpoint approach from 154 yards left him a simple two-footer to take the solo lead.

He saw a 20-foot eagle putt slip by at the par-five 18th but tapped in for his seventh birdie of the round and a 36-hole 12-under par total of 128.

US Open champion and overnight co-leader Woodland said he had to dig deep for his 66 to keep in touch with Woods.

"It was a grind all day," said the 35 year-old. "I didn't have my best stuff today. Fortunately I made three big putts there on 16, 17 and 18 which was awesome."

Friday's postponed round finally began at 10am Saturday on a weather-ravaged course with bright sunshine helping to dry the turf.

A pond to the left of the 10th fairway had expanded into a lake, forcing officials to move the tee forward, and a 376-yard par four became a 140-yard par four.

Local favourite Hideki Matsuyama immediately took advantage of the tiny 10th with an eagle two but trod water thereafter to finish four shots behind Woods.

World number two Rory McIlroy had a ragged two-over 72 on Thursday but he too opened with an eagle at the 10th to get back to level par.

A birdie four at the long 14th kept up the momentum and two more gains at 16 and 18 saw him turn in 31 and his way to a 65 to be three-under total, nine behind Woods.

American Keegan Bradley, the 2011 US PGA Championship winner, stormed up the leaderboard with a seven-under 63, the best round of the week, to position himself in Sunday's final group with Woods and Woodland at eight-under par.

The first US PGA Tour event in Japan is destined to finish on Monday. "Well, it's going to be a long one and we're going to play it from sun-up to sundown," said Woods.

"Probably looking to get somewhere near 27 holes in tomorrow. Hopefully I can play well and get myself right there."