Tiger Woods has unfinished business on his hands at this week's US PGA Championship.

The American world number one launches his title defence at Southern Hills Country Club this week in resolute mood to avoid ending the year without a major victory.

"This is your last opportunity to win one if you haven't had one yet," three-times champion Woods said. "This is the deepest field we play in all year and it's a great challenge.

"I've been in this position before where I haven't won one and was able to get the last one. Hopefully that will happen again this year."

Woods, a 12-times major winner, has completed only three seasons without a grand slam title since turning professional in late 1996.

He ended his 1998 campaign empty-handed after embarking on the first swing change of his career and failed to claim a major in 2003 and 2004 while going through a second swing overhaul.

Woods had also faced a fruitless major season in 1999 before going on to clinch his first PGA Championship crown at Medinah.

Since then, he has racked up a further ten majors and is a red-hot favourite at Southern Hills after cruising to an eight-stroke victory at the WGC-Bridgestone Invitational.

"It [my game] does feel pretty good," Woods added. "I made some nice strides last week, headed in the right direction and I am really looking forward to this week."

Despite having won four titles on the 2007 PGA Tour, the 31-year-old American conceded he would not be entirely happy with his season unless he triumphed this week.

"Golf-wise it's been pretty good but not great," added the world number one, who has posted eight top-ten finishes in 12 starts, including runner-up spots at the Masters and U.S. Open.

"I just think the major championships are valued that highly, and I've come close. Just haven't got it done yet."

Woods, who also won the PGA Championship at Valhalla in 2000 and at Medinah last year, has been frustrated by his inability to combine good ball-striking with good putting in the same week.

"It's just like, can I get the two together, somehow," he said. "It just hasn't materialised for some reason consistently enough."

Woods is scheduled to tee off with fellow Americans and former winners Rich Beem and Bob Tway from the tenth hole in Thursday's opening round.

Reuters