Paul Casey increased his lead from four shots to six with a superb start to his final round at the Abu Dhabi Championship today. Casey, back at the scene of his last victory two years ago, birdied the opening two holes and then added another on the 454-yard sixth to move to 22 under par.

Defending champion Martin Kaymer was still in second spot but had been caught by Padraig Harrington and Swede Johan Edfors. Harrington, tied for eighth overnight, birdied five of the first eight holes.

Casey, as he did on the second, two-putted the long eighth for another birdie, but Kaymer matched it and then struck a glorious approach to three feet on the next and cut the gap back to five.

He was out in 33, but Casey turned in 32 and it did not look as though Harrington was a threat after the British Open and US PGA champion bogeyed the ninth.