Els was in imperious form all week

South Africa's Ernie Els set a new PGA Tour scoring record for 72 holes in winning the season-opening Mercedes Championships in 31 under par.

The world number three carded a six-under-par 67 in the final round to continue his sparkling form of the opening three days.

His four round total of 261 was a new Tour record in relation to par, beating the 29-under total for 72 holes of Joe Durant in the 90-hole Bob Hope Chrysler Classic two years ago.

It was Els' 11th PGA Tour victory, and he pulled clear of KJ Choi over the closing holes to win by eight shots from the South Korean and American Rocco Mediate.

The 33-year-old only led by two shots at the start of play and only one with eight holes to play.

FINAL SCOREBOARD

-31 Ernie Els -23 Rocco Mediate, KJ Choi -22 Retief Goosen, Vijay Singh -21 Jonathan Byrd, Jim Furyk, Chris Riley, Bob Estes -20 Gene Sauers, Jerry Kelly

Collated scores

But he eased away to record the most decisive Tour victory since Mark Calcavecchia won the 2001 Phoenix Open, also by eight shots.

"I've had some good weeks in my career," Els said. "But to shoot 31 under par... I obviously haven't done that - nobody's done it."

Choi carded a course-record 11-under 62 on Saturday and began the back nine of the final round with consecutive birdies.

But he bogeyed the 13th and 14th holes and had to settle for a share of second on 23 under.

He was joined in runners-up spot by Mediate, who matched Jonathan Byrd for the lowest round of the day with a 63.