Tiger in the mix at National

Tiger Woods stormed into contention at the AT&T National with a four-under-par third round to close within a stroke of leader Brendon de Jonge.

In an unusual turn of events, spectators and most volunteers were banned from the Congressional Country Club course after storms over the weekend upended trees all over the course.

After chainsaws helped to clear the carnage in the morning, Woods revelled in the more serene surrounds with four birdies in his 67 to join countryman Bo Van Pelt (67) and South Korean Seung-Yul Noh (69) at six-under in the clubhouse.

Zimbabwean De Jonge carded three birdies and a bogey in his round of two-under 69 to lead at seven-under heading into the final round, but was upstaged on the day by Woods' ominous bogey-free round.

Woods, who won the tournament at this course in 2009, will be gunning for his third win of the year, while De Jonge is aiming for his first on the PGA Tour.

American Billy Hurley III soared up the leaderboard with the day's best round (five-under 66) to sit in a tie for fifth at five-under with overnight leader Hunter Mahan, who could only manage a two-over 73.

Venezuela's Jhonattan Vegas is a shot further back in outright seventh after firing a three-under 68, while American quartet John Mallinger, Ryan Palmer, Robert Garrigus and Pat Perez are at three-under.

Australians Jason Day and Marc Leishman - who won last week's Travelers Championship - are among a group of seven players not far away at two-under.

Day, looking to break back into the world's top 10, birdied the eighth and 16th either side of a bogey at the 10th.

Fellow Australians Adam Scott (one-under) and Rod Pampling (even) remain in the top 30.