Tiger Woods' late replacement Graeme McDowell made his impact felt at the Chevron World Challenge as he took a share of the lead heading into the final round in California.

Fellow Irishman Pádraig Harrington and European number one Lee Westwood of England are nine under following respective rounds of 70 and 69, with American Jim Furyk (67) and England's Ian Poulter (71) a further shot back.

McDowell was only called into the 18-player field at Sherwood Country Club on Monday, when tournament host Woods withdrew citing injuries sustained in the car crash that made headlines around the world eight days ago.

He now shares the 54-hole lead with US PGA champion Y E Yang of Korea following a third-round, six-under-par 66 at the course near Los Angeles.

McDowell and Yang, who both flew in from China having played in last weekend's World Cup at Mission Hills, take a one-shot lead at 10 under par into the final round, the Korean having fired a 71 having led at halfway by two shots.

American duo Sean O'Hair (71) and Kenny Perry (72) made it seven players within three shots of the lead, finishing the day on seven under.

McDowell's round contained an eagle, seven birdies, one bogey and one double bogey as the he  remained the only player in the 18-man field to improve on his score in every round.

"It was a funny one. I turned at one under par and was just cruising, nothing really happening and then I birdied 10, 11, 12 yesterday and did the same today," McDowell told NBC television.

"Then I hit a really good three-wood to 13 and made the putt for eagle and away we go.

"It was a fun day, I've been feeling really good about my game coming into this week and it was nice to continue playing well."

McDowell had an eagle putt at the 11th that rolled inches past but he gave himself another chance on the next par-five at the 13th, reaching the green in two before making the putt to take the outright lead at 11 under, two shots ahead of Harrington.

"I was about 254 (yards) to the front (of the green) and hit a three-wood about as good as I can hit and I set myself up with a nice eagle chance again," McDowell said.

"I'm feeling really good with the putter in my hand and I made some really nice putts today.

The birdies continued with his 18th of the week at the par-three 15th where McDowell sank a long putt but he wobbled as he neared the clubhouse, double bogeying the par-five 16th.

Having found a fairway bunker off the tee, his attempt to lay up only found the creek crossing the fairway and after a penalty drop his next shot found dirt under a greenside tree on the way to a double that brought him back into a share of the lead at 10 under with Harrington.

There was further trouble when McDowell missed the 18th green from the middle of the fairway and was forced to play out of a deep greenside bunker, only to save par with another lengthy putt.

"It's a funny golf course," he said. "It offers up lots of chances but if you get sloppy and (the 16th) was sloppy.

"I had an average lie in the trap and I'm not going to make any excuses it was a pretty awful shot. I just hit it about a foot behind, way fat.

"But it was nice to finish the day with a par save. It would have been a horrible finish to the day to make bogey at the last as well."