Lee Westwood carded back-to-back birdies early in his World Golf Championships-HSBC Champions final round to race into a three shot lead at Mission Hills.

Level with South African Louis Oosthuizen at the start of the day, the World Number Four from England found himself leading on his own when the South African bogeyed the first.

The 39 year old then pulled clear with a gain at the long third, followed by a magnificent approach to five feet at the fourth where, having seen his playing partners miss their respective birdie chances, Westwood confidently holed the putt.

That took Westwood to 20 under par, three ahead of Oosthuizen and the third member of the final group, Phil Mickelson, who birdied the first and third.

Open Champion Ernie Els and Ryder Cup hero Ian Poulter were both two under for the day through four to share fourth on 16 under.

Westwood was looking for his first WGC title in his 41st event – more than any other player – but his lead was quickly eradicated at the par three fifth when his tee shot ran off the green and he three-putted after chipping to 25 feet for a double bogey, as Oosthuizen birdied from 30 feet.

There was a quick response from Westwood, who birdied the sixth from 20 feet to reach 19 under and Oosthuizen joined him with a five footer at the long seventh.

Poulter and Els had already birdied there and they share third place as the playing partners holed putts of 25 and 20 feet at the eighth to reach 18 under, with Mickelson joining them when he picked a shot up at the seventh.