Aaron Baddeley did his best to remain in contention during the third round of the Buick Invitational but it was all to no avail as Tiger Woods extended his sizeable lead. Not content with a four shot lead at the halfway point of the tournament, the world No. 1 doubled his lead on the field with a six-under par round of 66. Woods is now at 18-under-par and leads the $5.5 million (AUD) event by eight strokes over Stewart Cink. Cink shot a three-under 69 at the Torrey Pines South Course to move to 10 under, with Joe Durant a further shot back on nine-under after firing a 67. Baddeley shot a one-under par 71 to share fourth spot with Justin Leonard, Doug Labelle and Boo Weekley on seven-under. Stuart Appleby is a further stroke behind at six-under par while Steve Elkington shot a round of 69 to move up to five-under alongside John Senden. Woods&apos eight stroke lead after three rounds is the biggest in the tournament&aposs history, surpassing the five stroke advantages held by Gene Littler in 1954, Bob Goalby in 1967 and JC Snead in 1976. The world number one also tied the 54-hole tournament record, first set by Woody Blackburn in 1985. Woods had a four-stroke to begin the third round and shot a two-under 34 on the front nine. He added four birdies on the back nine in a bogey-free round. It was his 19th consecutive round in the 60s. The last time he was in the 70s was in September in the first round of the Deutsche Bank Championship, where he finished tied for second. The final round is in danger of being cancelled because of heavy rains forecast for most of the last day.