Back-to-back bogeys by Tiger Woods handed England's Robert Rock an unexpected two-shot lead early in the Abu Dhabi HSBC Championship final round.

The two overnight leaders both birdied the second and third, but then Woods missed the next two greens and failed to get up and down on either occasion.

Rock, 117th in the world, was 13 under par and Woods had been joined in second place by Northern Ireland's US Open champion Rory McIlroy, who birdied the second and fifth.

Rock went three clear with a seven-foot birdie putt on the sixth and Woods had to work hard to keep his deficit to that after losing his ball control in the windier conditions.

By the turn, though, the gap was back to one. Rock was twice in rough on the long eighth and bogeyed, then Woods made a seven-footer of his own for birdie on the ninth.

They turned at 13 under and 12 under respectively, while Scot Paul Lawrie was alone in third two back and McIlroy, having bogeyed the short seventh, three behind with Dane Thomas Bjorn and Italian Francesco Molinari.

Graeme McDowell was too far back to challenge for the title, but a hole-in-one on the 12th - the third of the week there - brought him to eight under and earned him an annual three-night stay in the five-star Emirates Palace hotel for life like Sergio Garcia and Jose Manuel Lara.