(Reuters) - Former world number one Vijay Singh turned back the clock by firing a six-under 66 to seize the second round clubhouse lead at the BMW Championship on Friday.

With heavy rain forecast for later in the day, play started early at Crooked Stick Golf Club and Singh went right to work mixing seven birdies with a single bogey for a two day total of 13-under 131 in the penultimate FedExCup playoff event.

The smooth swinging Fijian, who started his day one shot off the lead and in a share of second place with Tiger Woods, began on the back nine and was quickly on the move with birdies at the 11th and 15th before grabbing the lead with four consecutive birdies from the 18th.

His only bogey came at the par-four fourth but then signed off with another birdie at the last to secure a one shot lead over American Ryan Moore, who carded a six-under 66 for the second consecutive day to get to 12-under.

Singh, a triple major winner who will turn 50 in February, has won just about everything there is to win in golf including the 2008 FedExCup title and the $10 million bonus but has not been in the winner's circle for four years.

World number one Rory McIlroy of Northern Ireland, who shared the overnight lead with three other players, was also at 12-under with three holes to play.

Briton Lee Westwood rocketed into contention with the round of the day, a seven-under 65 that featured six birdies, an eagle and one bogey to sit two off the pace while South Korea's Noh Seung-yul (66) is in the clubhouse at 10-under 134.

There will be no cut at the BMW Championship with all 70 golfers in the elite field vying for one of 30 spots in the September 20-23 Tour Championship finale in Atlanta where the overall points winner gets a $10 million bonus.