American Nick Watney maintained a two stroke advantage over compatriot Ryan Moore at the World Golf Championships-HSBC Champions on Friday morning with World Number One Tiger Woods and a resurgent Paul Casey in hot pursuit on a another sun drenched day in Shanghai.

Watney claimed the overnight lead with a sublime course record equalling eight under par 64 on Thursday and the Buick Invitational winner picked up where he left off with an early gain over his opening four holes at Sheshan International Golf Club to move onto nine under.

Wyndham Championship winner Moore also took advantage of the calm scoring conditions to birdie the second and remain one place behind Watney, a shot clear of Woods and Casey.

Two-time HSBC Champions runner-up Woods survived finding trouble off the first tee to birdie his opening hole, while Casey continued to show he is returning to his best following the rib injury which sidelined him for three months and was one under through five.

But The Race to Dubai contender Martin Kaymer and Irish Open champion Shane Lowry, tied second overnight with Moore, slipped off the pace after enduring disappointing starts.

Kaymer, second on The European Tour Order of Merit with just three events remaining, is still battling the foot injury which sidelined him for two months and dropped a shot on his fourth hole of the day to slip back to five under, while Lowry ensured a nightmare opening nine holes and plummeted to three under.