US Tour:Tiger Woods eased himself into a comfortable four-stroke lead halfway through the final round at the Tour Championship.

Woods recovered from a slow start to pick up three birdies and improve to 21 under par par at the turn in pleasant conditions at East Lake.

Fellow American Mark Calcavecchia remained in second place at 17 under after nine holes, with US Masters champion Zach Johnson another two shots back, also after nine holes.

Sergio Garcia was the best European, seven adrift back after nine holes.

Padraig Harrington went out in three over, but birdied the 14th to get back to eight under for the championship.

Woods looked shaky early on, pushing his tee-shot at the par-three second and making bogey.

He also was in danger of dropping a shot at the third but made a 10-foot putt to save par, before settling down and playing to sort of golf that took him to the front in the first place.

With three birdies in four holes from the sixth he eased away from the field, seemingly on his way to his fourth victory in his past five starts.

Meanwhile, on the Champions Tour, Des Smyth fired a final round of five-under-par 67 to claim a top-five finish in the Greater Hickory Classic at Rock Barn Golf Club in North Carolina.

That will help the Irishman to consolidate his position in the top 30 of the moneylist as he fights to retain his tour card.

RW Eaks was setting the pace on 16 under, three clear of Jay Hass, Rod Spittle and Scott Simpson.